Abstract: Abstract This study was conducted to monitor the effectiveness of seed priming with cold plasma and supplementation of rooting medium with SiO2 nanoparticle (nSi) on growth, physiology, and anatomy of Astragalus fridae. The plasma-primed seeds (surface power densities of 0.84 W cm−2; 0, 30, 60, and 90 s) were cultured in medium containing nSi (0, 5, 40, and 80 mg l−1). Ultra-structural analysis manifested the nSi uptake and transportation. The high doses of bulk Si adversely affected biomass and vigour index, while response to the nSi was partially different. The nSi5 amplified the growth-promoting roles of the plasma. The nSi80 treatment slightly diminished the chlorophyll content, which was mitigated by the plasma. The carotenoid content was rectified in the plasma and/or nSi-treated seedlings. The plasma and nSi treatments led to stimulations in activities of nitrate reductase in leaves and roots. The plasma treatments provoked the drastic stimulations in the catalase activities in both roots and leaves, while the effects of nSi in these organs were contradictory. Furthermore, stem and root diameters and differentiation pattern of xylem and phloem were modified. The findings provide a theoretical basis for exploiting in plant science and related technologies. Moreover, the available plasma-generating devices could be scaled up for treating plant tissue in in vitro condition. PubDate: 2019-03-21
Abstract: Abstract Drought is a vice to world crop production, exponentially enhanced by global climate change. Rice, a basic food crop for a major chunk of world populace, is largely affected by environmental challenges such as drought, salinity and heavy metal. This study brings to limelight differential drought tolerance capacity of rice varieties indigenous to North East India, a hot bed of indica rice diversity. Initial screening of rice varieties were performed through physiological dose-dependent studies under PEG (0%, 10%, and 20% which is equal to osmotic potential values of 0.001, 0.54 and 1.09 MPa, respectively), induced drought stress for three time intervals of 1, 3 and 5 days. Hierarchical clustering of the parameters on which the cultivars were analysed revealed Tampha and KMJ 1-12-3 to be relatively more tolerant whereas Chandan and Ketaki Joha as the sensitive ones. Biochemical studies for hydrogen peroxide (H2O2), proline, lipid peroxidation (MDA), lipoxygenase (LOX), superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (POX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and glutathione reductase (GR) were then performed on two cultivars (Tampha and Chandan) to elucidate the differential tolerance to drought, focusing on anti-oxidative response mechanism. The biochemical fingerprint showed significantly lower accumulation of H2O2 and MDA; higher accumulation of proline; and higher activity of SOD, CAT, DHAR, MDHAR and GR in the tolerant variety Tampha when compared to Chandan. In addition, alteration of chlorophyll fluorescence due to stress was also monitored to ascertain the variation in photosynthetic efficiency between the tolerant and sensitive cultivars. Tampha showed better photosynthetic activity in comparison to Chandan as quantified by measuring chlorophyll fluorescence. This manuscript thus throws new light into the drought stress response of the varieties from North East India with global implications. PubDate: 2019-03-21
Abstract: Abstract The freezing tolerance of seven olive cultivars, including Amphisis, Conservallia, Koroneiki, Manzanilla, Gorgan, Shengeh, and Rashid, was compared, and its correlation with some biochemical and physiological factors was investigated. From each cultivar, leaf and stem samples were collected and sorted into two groups: the first was exposed to various freezing temperatures to indicate its freezing tolerance in terms of lethal temperature (LT50) values by several approaches (electrolyte leakage, maximum quantum yield of PSII photochemistry, and tetrazolium staining test); the second was prepared for some biochemical and physiological parameter analyses. Of all cultivars, Amphisis and Shengeh showed the highest freezing tolerance, the maximum soluble carbohydrate and proline content, DPPH (1, 1-diphenyl–2-picrylhydrazyl) scavenging capacity, the minimum malondialdehyde (MDA), and relative water content (RWC). Conservallia, Gorgan, and Manzanilla cultivars could moderately tolerate freezing temperatures, whereas Rashid and Koroneiki cultivars turned out to be freezing-susceptible. In olive bark and leaf, LT50 showed a negative correlation with soluble carbohydrate, proline content, and DPPH scavenging capacity and a positive correlation with MDA and RWC. Three indicators, i.e., LT50, osmoregulant content, and DPPH scavenging capacity, can contribute to screening the freezing-tolerant olive cultivars. PubDate: 2019-03-20
Abstract: Abstract Soil salinity is one of the major environmental stress factors limiting crops growth, development, and productivity worldwide. The aim of this study was to compare differences of salinity tolerance between diploid (cv. TY03209) and tetraploid (cv. TY03410) seedlings of sugar beet (Beta vulgaris L.) treated with various concentrations (0, 50, 100, 200, and 300 mM) of NaCl. Our results indicated that fresh weight (FW) and dry weight (DW) of shoot in tetraploid were remarkably higher than those in diploid when subjected to various concentrations of NaCl (except for FW under 200 mM). At 200 and 300 mM NaCl, tetraploid obviously accumulated less Na+ in its shoots and roots compared with diploid. However, there were no differences in K+ accumulation between tetraploid and diploid under salinity stress. Our results also showed tetraploid displayed a smaller Na+/K+ ratio and a stronger selective capacity for K+ over Na+ than diploid when exposed to high-salt stress (300 mM). Furthermore, it was observed that tetraploid possessed a bigger net K+ uptake rate and a smaller net Na+ uptake rate compared to diploid at high-salt condition. We also investigated the relative expression levels of six genes related to K+ and Na+ transport in roots of diploid and tetraploid by qRT-PCR method, and found that BvHKT1;1, BvNHX1, BvSKOR, and BvSOS1 were induced by additional 50 mM NaCl, and their transcript abundances in tetraploid were relatively higher than those in diploid. The expression level of BvAKT1 was down-regulated in tetraploid during 3–48 h of salt treatment, whilst basically remained unchanged in diploid. It was observed that the transcript abundance of BvHAK5 in diploid displayed the reduced trend with the prolonging of salt treatment time compared to tetraploid. In addition, soluble sugars contents were obviously higher in tetraploid than in diploid exposed to 100, 200, and 300 mM NaCl. Taken together, these results suggested that tetraploid exhibited more tolerant to salinity stress than diploid in sugar beet by accumulating less Na+ and more soluble sugars, and by maintaining lower Na+/K+ ratio and greater capacity of selective absorption for K+ over Na+. The results of this study provide insights into physiological and molecular consequences of polyploidization in sugar beet. PubDate: 2019-03-20
Abstract: Abstract The present study describes the impact of light-emitting diodes (LEDs) on synseed germination and subsequent synseed-derived seedling growth of Curculigo orchioides, an endangered medicinal plant under in vitro conditions. Shoot buds regenerated on Murashige and Skoog’s medium (MS) containing 4 mg/l 6-benzylaminopurine (BAP), and 3% sucrose were utilized for encapsulation. Encapsulation was achieved by suspending the excised shoot buds into sodium–alginate gel matrix and dropping them into 100 mM CaCl2 solution. Synseeds thus produced were incubated under different light conditions. Among the various light treatments, irradiation of synseeds with blue LEDs (BL) strongly influences the growth of the synseed-derived seedlings. A significant increase in length, fresh and dry biomass of the synseed-derived seedlings was observed under BL as compared to light treatments of conventional fluorescence lamps (FL) and a combination of blue and red LEDs with equal proportion (BRL, 1:1). The trifoliate leaf area and weighted density of leaves were measured from the digital images of synseed-derived seedlings using MATLAB® 2013a Image Processing Toolbox. Image analysis of the synseed-derived seedlings also revealed the improved growth in terms of increase in trifoliate leaf area and weighted density under BL. Exposure to red LEDs (RL) resulted in poor synseed germination and severely retarded the growth of the synseed-derived seedlings. The leaves of synseed-derived seedlings grown under BL had higher chlorophyll a, carotenoid, total phenols, and flavonoid contents than that of FL and BRL treatments. The synseed-derived seedlings developed under BL also displayed enhanced levels of antioxidant activity. Ex vitro performance of the synseed-derived seedlings raised under BL was found to be better with improved plant canopy as expressed in terms of increase in trifoliate leaf area and weighted density than other light treatments. The present study for the first time demonstrates the potential of BL irradiation on encapsulation technology with the ability of direct conversion of synseeds to synseed-converted seedlings leading to the vigorous growth of the plantlets which may make the encapsulation strategy ideal for supply of healthy plant propagules for transfer to field conditions and germplasm conservation. PubDate: 2019-03-18
Abstract: Abstract Fluorescent proteins (FPs) can be used for different purposes in plant transformation studies such as the evaluation and improvement of transformation parameters or the isolation of transgenic cells in the absence of selective agents. In this research, the applicability of green (GFP) and red (DsRed) fluorescent proteins in olive transformation has been investigated. Olive embryogenic callus was transformed with Agrobacterium tumefaciens AGL1 strain carrying pXK7FNF2 (harbouring the gfp gene), pXK7RNR2 (DsRed), or pXK7S*NF2 (gfp and β-glucuronidase) binary plasmids. After 3 months of selection in the presence of paromomycin, several resistant calli were recovered for each construct, obtaining transformation rates in the range of 2–8%. The expression of FPs was studied during the different stages of olive plant regeneration using epi-fluorescence and confocal laser scanning microscopy. GFP from pXK7SN*F2 plasmid could be easily detected in olive somatic embryos (SE) during proliferation whereas SE transformed with pXK7FNF2 showed weak GFP signal. After embryo conversion, plants transformed with both vectors were analysed, but GFP could be detected neither in leaves nor in roots. By contrast, DsRed was highly expressed in SE and could also be visualized in leaf and root tissues of regenerated plants using confocal laser microscopy and epi-fluorescence zoom microscope, respectively. In addition, pXK7RNR2 was used to transform a different olive embryogenic line, detecting DsRed expression in SE transformed from this genotype. These results show that FPs can be a useful tool in genetic transformation of olive embryogenic cells, being DsRed gene more useful than gfp for this purpose. PubDate: 2019-03-16
Abstract: Abstract Yield loss due to insufficient potassium fertilizer supply has been well documented; however, the information about the negative effect of potassium deficiency on crop yield caused by ecophysiological determinants is not enough. A field experiment with three K treatments (severe K deficiency treatment, K1; moderate K deficiency treatment, K2; and sufficient K supply treatment, K3) was conducted to (1) assess the effects of potassium deficiency on green leaf area index (GLAI) reduction; (2) quantify the contributions of single leaf area, leaf senescence, and leaf appearance to GLAI reduction under potassium deficiency; (3) reveal the changes in the contributions of accumulated radiation interception (RIacc) and radiation-use efficiency (RUE) to above-ground biomass (AM) decrease of oilseed rape under different K supplies. GLAI was restrained due to potassium deficiency, with a reduction ranging from 10.6 to 45.4%. The reduced single leaf area and accelerated leaf senescence caused by potassium starvation accounted for 5.9–23.7% and 2.4–29.0% reduction in GLAI, but delayed leaf appearance rate contributed little. The RIacc during the seedling stage in the K1, K2, and K3 treatments was 101.2, 110.7, and 120.0 MJ m− 2, respectively, and the RUE in the K1, K2, and K3 treatments was 1.03, 2.22, and 2.98 g MJ− 1, respectively, which caused a 61.7% and 48.2% reduction of the final harvested AM in the K1 and K2 treatments compared with the K3 treatment. When AM reduction was less than 24.8%, RIacc was the main determining factor; however, it transferred to RUE when biomass decreased more. In conclusion, GLAI decreased due to potassium starvation was mainly caused by the reduced single leaf area and accelerated leaf senescence, and the relative contribution of RIacc and RUE to AM decline was related to the degree of potassium deficiency. PubDate: 2019-03-16
Abstract: Abstract Global warming and other climate change eventslead to a constant rise in ambient temperatures. Exposure to higher than optimal temperatures is negatively affecting sexual reproductive performance, leading to low seed set and a consequent yield reduction. Pollen is considered more heat stress sensitive than both vegetative tissues and the female gametophyte. But this sensitivity to heat stress is not uniform during pollen development and function. Pollen grains are more sensitive at the early stages of development (anther wall development, microsporogenesis and microgametogenesis) than pollen at later stages (pollen maturation and anther dehiscence) or during the progamic phase (pollen hydration, germination, growth and guidance of the pollen tube). Heat stress is thought to be sensed by four types of sensors including cyclic nucleotide-gated calcium channels (CNGC), unfolded protein response (UPR) in endoplasmic reticulum (ER) and cytosol and histone proteins in the nucleosome. Each sensor activates pollen heat stress response (HSR) through reprogramming of the transcriptome, proteome and metabolome. HSR restores cellular and metabolic homeostasis in the pollen and avoids damage elicited by heat stress. In the first part of this review, we have summarized current findings regarding the effect of heat stress on different stages of pollen development and performance. In the second part, the responses of pollen to heat stress are discussed. Finally, directions for future research on pollen HSR are discussed with a focus on breeding crops with improved thermo-tolerance, thus capable of withstanding the current context of global warming. PubDate: 2019-03-15
Abstract: Abstract Chitosan as natural product might have potential application in the production of Origanum majorana “Marjoram”, a known historic plant with economic importance in the agriculture and pharmaceutical industries. Under three irrigation periods (1, 3, and 5 days) in marjoram plants for 8 weeks, chitosan was applied as water solution at 50, 200 and 500 ppm. Chitosan increased selected morphological parameters and associated with elevated physiological and molecular performance. Enhanced metabolism of the treated plants was expressed as increased rates of stomatal conductance and photosynthetic rates. In addition, soluble sugars and proline levels were higher. Elevated expression of MnSOD Cu/ZnSOD, FeSOD, APX, DREB2 and ERF3 s were also detected. Further elevated expression of CYP71D179/182 and CYP71D178 PII, essential oil composition-related genes, was also found. The SOD and APX enzymes were more active and there were reductions in the levels of reactive oxygen species. Thymol and cis-Sabinene were higher in treated plants essential oils. Chitosan may alleviate water stress in marjoram by enhancing the metabolism and stress related genes in treated plants. PubDate: 2019-03-14
Abstract: Abstract SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) is a vital flowering signal integrator to promote flowering, which is inhibited by a MADS-box transcription factor, SHORT VEGETATIVE PHASE (SVP). However, it remains elusive about how SOC1 interacts with SVP in flowering pathways of Brassica juncea. Here, B. juncea SOC1 (BjuSOC1) gene was cloned and it expressed differently between stem apexes and leaves during the low-temperature vernalization and long-day photoperiod pathways. Yeast two-hybrid and BiFC assays indicated that BjuSOC1 directly interacted with BjuSVP in vitro and in vivo. Interestingly, further studies indicated that mutants of BjuSOC1K108V, BjuSOC1R109L, BjuSOC1C137K could no more interact with BjuSVP, and BjuSVPR137L also led to loss of the protein interaction. It suggested that the 108th, 109th, and 137th of BjuSOC1 and 137th of BjuSVP regulated the protein interactions between BjuSOC1 and BjuSVP. The results provided valuable information for further study on the control of flowering time in B. juncea. PubDate: 2019-03-14
Abstract: Abstract Artemisia annua L. is the main source of artemisinin, currently the most effective treatment for malaria. However, an affordable and abundant supply of artemisinin remains elusive. Trichoderma is a biocontrol agent that stimulates plant growth and defense responses, and improves soil quality. To date, relatively few studies have focused on improving leaf biomass and artemisinin production in A. annua using Trichoderma. To investigate the role of T. asperellum ACCC30536 in improving the artemisinin yield of A. annua, field-grown A. annua was inoculated with T. asperellum conidia and grown for 60 days. The results showed that leaf artemisinin concentration and dry weight were increased significantly after inoculation. The optimal inoculation dose was 200 mL of conidia suspension at 1 × 107 colony-forming units (cfu)/mL, the highest artemisinin concentration was 8.83 mg/g, and the highest artemisinin production was 70.6 g on day 50. The results of qRT-PCR revealed that expression of genes encoding key enzymes for artemisinin biosynthesis, namely HMGR1, FPS, ADS, CYP71AV1, CPR, DBR, DXS1, and DXR1, was generally upregulated during days 20–50 following induction by Trichoderma. In addition, the moisture, pH stability, organic matter content, and availability of nitrogen, phosphorus, and kalium in inoculated soil were significantly improved. Thus, application of T. asperellum ACCC30536 may offer a novel approach for improving artemisinin production by upregulating the expression of key enzymes for artemisinin biosynthesis, increasing leaf yield, and improving soil fertility. PubDate: 2019-03-14
Abstract: Abstract Brassica napus is a polyploid of certain research and economical value. Resynthesizing B. napus with diploid B. rapa and B. oleracea is essential for Brassica research because of the limited genetic background of B. napus. Considering that polyploids possess better agronomic traits and resistance compared with the corresponding diploids, we investigated drought tolerance after polyploidization of B. napus and revealed the epigenetic differences between polyploids and diploids. After drought stress, B. rapa and first-generation of synthesized hybrids (F1) were more wilted than B. oleracea and F2–F4 generations. However, the relative water content and water retention in F1 were better than others after drought stress. The increased number of partially opened and closed stomata in F1 was not as significant as that in F2 and F3, but stomata density in F1 was lower than F2, and the stomatal size in F1 was significantly reduced than F3. Physiological parameters varied among different generations of B. napus and diploid parents, and most of these parameters in hybrids were higher than B. rapa and lower than B. oleracea. However, the peroxidase activity in F3 and F4 was significantly higher than both parents, and the malondialdehyde content in F3 and F4 was lower than both parents, indicating that F3 and F4 might be more adaptive to oxidative stresses than other generations. DNA methylation level was decreased in F2 and F3 compared with F1, and then increased in F4. Methylation-sensitive amplified polymorphism analysis revealed that DNA methylation and demethylation broadly happened after drought stress. The methylation and demethylation level was F1 > F4 > B. oleracea > F2 > F3 > B. rapa and B. rapa > F4 > F3 > F2 > B. oleracea > F1, respectively. The epigenetic changes under drought stress might be related to the different stress tolerances during B. napus polyploidization. PubDate: 2019-03-14
Abstract: Abstract The response of drought stress on morpho-physiological and biochemical characters was assessed in black gram genotypes in a pot culture experiment. Water stress was applied at flowering stage of the crop and various morpho-physiological and biochemical characters were analyzed under control and water stress conditions. The genotypes, water levels and their interaction varied significantly for majority of the traits quantified revealing the presence of substantial genetic diversity. Based on these studies, genotypes PGRU95016, COBG05, IPU99209, IPU941 and IPU243 were identified as tolerant to drought stress conditions. Photosynthesis, stomatal conductance, transpiration rate, total chlorophyll, proline content and peroxidase activity could be useful to screen for drought tolerance in black gram. PubDate: 2019-03-06
Abstract: Abstract In this study, changes in gene transcription during adventitious root formation in hardwood cuttings of Marubakaido apple rootstock were examined by RNA-seq analysis. In line with above, 11 genes related to root development were identified as candidate genes for modulator of adventitious root formation. Among them, the induction of ABC transporter G family member-, NO VEIN-, and Auxin transporter-like protein 2-like genes, which are known to be associated with cellular auxin distribution and maintenance of root meristem niche, before the appearance of the first visible adventitious root formation in Marubakaido was revealed by quantitative RT-PCR. In addition, we conducted comprehensive co-expression network and MAPMAN analysis, and found a relationship between adventitious root formation and phytohormones such as cytokinin and abscisic acid (ABA). Finally, we also found the genes encoding receptor of plant peptide hormone, such as Barely any meristem 3-like gene (a receptor of plant peptide hormone CLAVATA45) and phloem intercalated with xylem-like gene (a receptor of the plant peptide hormone known as tracheary element differentiation inhibitory factor or TDIF), assuming the association of plant peptide hormone with adventitious root formation in Marubakaido apple rootstock. CLAVATA and TDIF are known as plant peptide hormones related to root stem cell and vascular differentiation, respectively. Therefore, we conclude that the process of adventitious root formation such as the maintenance of stem cell and vascular differentiation in Marubakaido apple rootstock was controlled by complex plant hormone signalling, including auxin, cytokinin, ABA, and plant peptide hormone. PubDate: 2019-03-04
Abstract: Abstract Fusarium oxysporum f. sp. vanillae (Fov), the most devastating pathogen of Vanilla planifolia, an important orchid used in the food industry, causes stem and root rot. Vanilla genotypes that are resistant to Fov currently do not exist, so vanilla plants that are resistant to this fungus are needed. In vitro selection offers an effective means to accomplish this objective. Resistant shoots were selected on Murashige and Skoog medium (MS) containing 8.88 µM of 6-benzyladenine and various concentrations of Fov culture filtrate (30, 40 and 50%, v/v). The control treatment (0%) was exclusively MS medium without any culture filtrate. After two 60-day selection cycles, 40 resistant shoots were obtained. In vitro, about 35% of the shoots were resistant to 50% Fov culture filtrate, while in vivo tests indicated that 26.6% of the plants had acquired resistance to the pathogen under greenhouse conditions after 9 weeks. The protocol employed in this study, which forms part of a wider genetic improvement program for this orchid, allowed Fov-resistant V. planifolia plants to be obtained within 420 days. PubDate: 2019-03-02
Abstract: Abstract Pearl millet is one of the most important C4 panicoid millet crops grown in dry and arid regions of India and West Africa. Drought is one of the major limitations to its growth potential. Therefore, selection of drought-tolerant cultivars through in vitro screening can be an important approach for crop improvement programmes. An experiment was conducted on six pearl millet genotypes with two different levels of osmotic stress treatments, i.e., control and 20% polyethylene glycol (PEG) 6000 at early seedling stage for eight seedling traits and proline content, while 30% PEG at late seedling stage for proline and malonaldehyde (MDA) content and gene expression analysis. Analysis of variance (ANOVA) showed significant treatment effects on all early seedling traits with respect to treatment x varietal interaction. Our results showed a relative decline for different seedling traits in individual genotypes with increased osmotic stress. TT-1 showed a maximum reduction in almost all traits while the minimum decline was noted in PRLT2/89-33. Further, proline and MDA accumulation in control and 30% PEG-6000-treated seedlings at late growth stages were in confirmation with the observations recorded at early seedling growth stages. Expression analysis using quantitative real-time (qRT)-PCR of three antioxidative genes namely, ascorbate peroxidase (APX), glutathione reductase (GlutR) and superoxide dismutase (SOD) also confirmed higher osmotic stress tolerance of PRLT2/89-33 seedlings. Overall results suggested that selection for any of the above traits at early or late-seedling growth stages may prove useful for crop improvement programs directed towards developing stress-tolerant cultivars. PubDate: 2019-03-01
Abstract: Abstract The performance of rhizobia in soybean nodules under drought stress conditions was analyzed using five Bradyrhizobium strains selected according to the osmotic stress tolerance in liquid medium. The effect of selected rhizobial strains on root and nodule antioxidant response and symbiotic performance was evaluated in a soil pot experiment under different levels of drought stress (0, 3, 5, 7 days withholding water). Drought stress increased the guaiacol peroxidase (POX) and ionically cell wall-bound peroxidase (POD) activity, antioxidant capacity, soluble protein content in roots and nodules, reduced the shoot dry weight (SDW), and increased the nitrogen content in the roots. Under water deficit conditions the highest increase of antioxidative parameters was recorded in the nodules of strain 216, and the lowest in roots and nodules of the plants inoculated with strain 511. Inoculation with strain 511 resulted in significantly lower SDW, root dry weight (RDW) and plant nitrogen content, while application of strain 216 resulted in the highest shoot attributes. Rep-PCR characterization and 16S-23S rDNA intergenic region sequencing emphasized the differences in strains genomic organization, especially for the 216 strain showing the higher tolerance to osmotic stress. The results implicate similarity between strain performance under osmotic stress in liquid medium and in symbiotic association under drought stress. The results also suggested important contribution of rhizobial strains in enhancing antioxidative response under drought stress and in symbiotic effectiveness, indicating more sensitive and tolerant symbioses. PubDate: 2019-02-22
Abstract: Abstract Tolerance to the pink snow mould resulting from Microdochium nivale infection is an essential trait of triticale (x Triticosecale) for winter survival. In the present study, we aimed to verify whether the presence and concentration of free and cell wall-bound phenolic acids are important factors in triticale responses to M. nivale infection. Based on 3 years’ testing of triticale tolerance, 2 out of 92 doubled haploid triticale lines derived from ‘Hewo’ × ‘Magnat’ F1 hybrid were selected, which are the most tolerant and the most sensitive to M. nivale infection. Plants were grown along with their parents under controlled conditions, pre-hardened and cold-hardened, while non-hardened plants served as the control. Hardened plants were covered with the artificial snow-imitating covers and inoculated with M. nivale mycelium, while the control plants were treated the same way except the infection. The aim of the study was to identify differences in the initial content and composition of phenolics under the influence of applied stresses. Conducted HPLC analysis showed that the most abundant were ferulic, rosmarinic, chlorogenic, sinapic, and trans-cinnamic acids. The contents of most of phenolics depended on genotype and growth conditions. Two cell wall-bound sinapic and trans-cinnamic acids, could be indicated as potentially related to the increased snow mould tolerance of winter triticale seedlings. A correlation between the total phenolic levels with the tolerance was not found; however, the proportion between the total levels of cell wall-bound and free phenolic compounds under low temperature could play a role prior to M. nivale infection. PubDate: 2019-02-22
Abstract: Abstract Globally, production of pineapple fruits reached more than 25 million tons in 2013. Therefore, many scientists are searching for new varieties and ways for the conservation of pineapple genetic resources. Cryoconservation in liquid nitrogen has been described as a suitable technology in many plant species. However, its potential effects in the subsequent plant growth in the field should be studied before large-scale implementation of cryopreserved germplasm banks. This short communication describes the field performance of cryopreserved shoot tip-derived pineapple adult plants grown in the field for 14 months. Three genetic materials [cv. MD-2; cv. Red Spanish Florencia; Hybrid 54 (Smooth Cayenne/Red Spanish)] were compared. The following treatments were established in the field: (1) conventional micropropagation-derived plants; (2) plants from shoot tips never exposed to liquid nitrogen but submitted to pre-cryostorage conditioning treatments; and (3) plants from shoot tips exposed to liquid nitrogen. Results indicated that shoot tip exposure to liquid nitrogen did not alter pineapple field performance which supports cryopreservation as an important tool for conservation of pineapple germplasm. As far as we know, this is the first publication of a detailed study of pineapple agricultural traits after cryopreservation. PubDate: 2019-02-20
Abstract: Abstract According to both the proline metabolic mutation context (p5cs 1-4) and the effective involvement of the durum wheat dehydrin transgenic context (DH2 and DH4) against salt stress, we report here some response elements that can give rise to clarification if there is duality between proline metabolic mutation context (p5cs 1-4) and the durum wheat dehydrin transgenic context for salt tolerance process acquisition. Furthermore, some physiological, biochemical and metabolic assessments were monitored. The studied lines (Wt, DH2, DH4 and P5CS1-4) share the same chlorophyll level (82, 76, 77 and 79, respectively), under MS medium. In MS–proline and MS–proline–NaCl media, the chlorophyll level of transgenic lines (DH2 and DH4) upgrades per comparison with Wt and P5CS1-4 (92, 96, 84 and 82, respectively). The same fact is observed in the MS–NaCl medium. The proline accumulation and also the P5CS activity determination give rise to proportional behaviors for both the studied lines under the studied cultural conditions. Those results and others described here give birth to two parameters, the global ROS scavenging system index (GI) and the system apparent velocity (µapp) giving proof of the enhancement of the capability to tolerate salinity in Arabidopsis transgenic plants. Eventually, the described fact is illustrated using the “Deming wheel” model. PubDate: 2019-02-20
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