Abiotic Stress Conditions Research Articles

When drought meets heat - a plant omics perspective.

Changes in weather patterns with emerging drought risks and rising global temperature are widespread and negatively affect crop growth and productivity. In nature, plants are simultaneously exposed to multiple biotic and abiotic stresses, but most studies focus on individual stress conditions. However, the simultaneous occurrence of different stresses impacts plant growth and development differently than a single stress. Plants sense the different stress combinations in the same or in different tissues, which could induce specific systemic signalling and acclimation responses; impacting different stress-responsive transcripts, protein abundance and modifications, and metabolites. This mini-review focuses on the combination of drought and heat, two abiotic stress conditions that often occur together. Recent omics studies indicate common or independent regulators involved in heat or drought stress responses. Here, we summarize the current research results, highlight gaps in our knowledge, and flag potential future focus areas.

Genome-wide characterization of the role of the KCS gene family in Allium fistulosum L. as regulators of abiotic stress responses

Cuticle wax is a defensive coating on the surfaces of plant tissues that helps shield them from both biotic and abiotic stressors. The 3-ketoacyl-CoA synthase (KCS) enzymes control the rate-limiting step in the synthesis of very-long-chain fatty acids (VLCFAs), thereby regulating wax biosynthesis. In the present study, a genome-wide approach was used to identify 31 members of the KCS gene family in Allium fistulosum that were classified into 9 groups through phylogenetic analysis. These genes were unevenly distributed throughout the A. fistulosum genome, and 7 (AfKCS1, AfKCS2, AfKCS4, AfKCS13, AfKCS17, AfKCS24, and AfKCS28) of them did not harbor any introns. Cis-acting regulatory element analysis revealed that all of these genes were associated with at least one hormone- or stress-responsive element, and heatmap analysis of the expression patterns of these AfKCS genes revealed that they were primarily expressed in the stems and leaf sheaths of A. fistulosum. Eight of these AfKCS genes that were highly expressed in leaf tissue samples harvested from A. fistulosum were further analyzed to detect changes in their expression in response to salt, drought, and low or high temperature stress exposure. All 8 were significantly upregulated in response to salt, low temperature, and high temperature stress, while 4 (AfKCS14, AfKCS15, AfKCS23, AfKCS26) were downregulated in response to drought stress, offering potentially valuable insight into the roles that they play in the context of abiotic stress resistance. Together these findings offer a new foundation for future analysis of the importance of members of the KCS gene family in A. fistulosum play under conditions of abiotic stress and other physiological settings.

Impact of Exogenous Melatonin Application on Photosynthetic Machinery under Abiotic Stress Conditions.

Inhospitable conditions that hinder plant growth and development encompass a range of abiotic stresses, such as drought, extreme temperatures (both low and high), salinity, exposure to heavy metals, and irradiation. The cumulative impact of these stresses leads to a considerable reduction in agricultural productivity worldwide. The generation of reactive oxygen species (ROS) is a shared mechanism of toxicity induced by all these abiotic stimuli in plants, resulting in oxidative damage and membrane instability. Extensive research has shed light on the dual role of melatonin in plants, where it serves as both a growth regulator, fostering growth and development, and a potent protector against abiotic stresses. The inherent potential of melatonin to function as a natural antioxidant positions it as a promising biostimulant for agricultural use, bolstering plants' abilities to withstand a wide array of environmental challenges. Beyond its antioxidant properties, melatonin has demonstrated its capacity to regulate the expression of genes associated with the photosynthetic process. This additional characteristic enhances its appeal as a versatile chemical agent that can be exogenously applied to plants, particularly in adverse conditions, to improve their resilience and optimize photosynthetic efficiency in every phase of the plant life cycle. An examination of the molecular mechanisms underlying the stress-protective effects of exogenous melatonin on the photosynthetic machinery of plants under various abiotic stresses is presented in this paper. In addition, future prospects are discussed for developing stress-tolerant crops for sustainable agriculture in challenging environments.

Efficacy of biofertilizers in different stress management of fruit crops- A Review

Biofertilizers are gaining widespread acceptance in agriculture due to their numerous advantages over chemical fertilizers. These environmentally friendly alternatives play a crucial role in enhancing soil health and fertility through various mechanisms. Biofertilizers consist of diverse microorganisms that can effectively promote plant growth and development, even under abiotic stress conditions. As a result, the utilization of biofertilizers is steadily increasing, especially with the escalating costs of chemical fertilizers and their adverse effects on soil health and crop yields. Certain microorganisms, such as Azotobacter, Azospirillum, Arbuscular Mycorrhizal Fungi (AMF) Gigaspora rosea, Pseudomonas, and Funneliformis geosporus, hold substantial potential for commercial use as biofertilizers to improve the growth and development of fruit crops. In-depth research has demonstrated that biofertilizers can significantly augment the biomass and productivity of various fruit crops. Their application in fruit crop production is particularly beneficial as they not only enhance growth but also confer improved resistance to abiotic stress factors like high temperatures, drought, salinity, and metal toxicity. This comprehensive review highlights the substantial promise of biofertilizers in mitigating abiotic stress and fostering sustainable practices in fruit crop cultivation.

Evaluation of secondary sexual dimorphism of the dioecious Amaranthus palmeri under abiotic stress

The evolution of secondary sex-specific traits of dioecious species under abiotic stress conditions has received limited research, especially in the case of Amaranthus palmeri, a fast adapting and highly competing plant. Here, we have examined the interactive effects of abiotic stress on mineral accumulation, chlorophyll a and b content, and the operating capacity of Photosystem II (PSII) in both male and female A. palmeri plants grown under three different intensities of white light, and under N, K or P deficiency. Mineral profiling of the leaves and stems (with inflorescence) highlighted intra- and intersexual differences in their accumulation pattern and mineral associations. Chlorophyll a and chlorophyll b were different between the male and the female plants, being slightly lower in the latter, at high light intensity towards maturity, or under K or P deficiency. Further, slight, although statistically significant differences were recorded in the chlorophyll a/b ratio, which was lower at the higher light intensity in the female, over that in the male, plants towards maturity. Chlorophyll fluorescence parameters, i.e., steady state and maximum fluorescence increased under high light intensity, whereas the PSII operating efficiency decreased in the female plants, indicating reduced PSII capacity. Sex-specific differences in A. palmeri showed a differential response to stressful conditions because of differences in their ontogeny and physiology, and possibly due to the cost of reproduction. We suggest that the breeding system of dioecious species has weaknesses that can be used for the ecological management of dioecious weeds without relying on the use of herbicides.

Endophytic Bacillus strains enhance biomass and bioactive metabolites of Gloriosa superba

Gloriosa superba L. is an economically important medicinal plant and variation in its colchicine content may be due to associated endo- and ectophytic beneficial microbes. Among them, endophytic bacteria contribute to enhancing plant growth, induce biotic and abiotic stress tolerance, and play a significant role in secondary metabolite synthesis. In the present study, 76 native endophytic bacteria were isolated from high and low-colchicine and gloriosine-containing chemotypes of G. superba rhizome and characterized for vegetative growth enhancement and abiotic stress mitigation. The screening has resulted in the selection of 23 plant growth-promoting (PGP) bacterial endophytes with abiotic stress tolerance. Most of these isolates belong to the Bacillus genera identification based on the 16S rRNA gene. Based on the significant enhancement in maize (Zea mays L.; as model host plant) under greenhouse conditions ten efficient bacterial strains were selected. Further, three endophytic bacterial strains, NBRI HYL5 and NBRI HYL8 (high colchicine and gloriosine containing chemotype), and NBRI LYN9 (low colchicine and gloriosine containing chemotype) were selected based on the survivability and enhanced 1-aminocyclopropane-1- carboxylate (ACC) deaminase activity, phosphate solubilization, biofilm, Indole acidic acid (IAA), exopolysaccharide, and alginate production abilities under different abiotic stress conditions. Finally, a greenhouse experiment was conducted to evaluate the effect of selected bacterial endophyte inoculation in G. superba for growth enhancement and secondary metabolite content. The results showed that plants treated with NBRI HYL5 and NBRI HYL8 significantly enhanced the colchicine content (97–98 %) and gloriosine content (70–73 %), respectively as compared with control. However, inoculation of NBRI LYN9 has demonstrated significant enhancement only in gloriosine content (79 %). In addition, NBRI HYL5 and NBRI HYL8 have demonstrated significant improvement in overall vegetative growth parameters, photosynthetic pigments, and total soluble sugar content. Colonization and persistence of selected endophytic bacteria in G. superba rhizome and shoot clearly depicted the involvement not only in enhancing the vegetative growth but also in enhancing the colchicine and gloriosine content. Overall, this study presents the beneficial role of endophytic Bacillus strains in enhancing the growth of G. superba and secondary metabolite content may lead to contribute in sustainable cultivation of economically important medicinal plants.

BRI1 EMS SUPPRESSOR1 genes regulate abiotic stress and anther development in wheat (Triticum aestivum L.).

BRI1 EMS SUPPRESSOR1 (BES1) family members are crucial downstream regulators that positively mediate brassinosteroid signaling, playing vital roles in the regulation of plant stress responses and anther development in Arabidopsis. Importantly, the expression profiles of wheat (Triticum aestivum L.) BES1 genes have not been analyzed comprehensively and systematically in response to abiotic stress or during anther development. In this study, we identified 23 BES1-like genes in common wheat, which were unevenly distributed on 17 out of 21 wheat chromosomes. Phylogenetic analysis clustered the BES1 genes into four major clades; moreover, TaBES1-3A2, TaBES1-3B2 and TaBES1-3D2 belonged to the same clade as Arabidopsis BES1/BZR1 HOMOLOG3 (BEH3) and BEH4, which participate in anther development. The expression levels of 23 wheat BES1 genes were assessed using real-time quantitative PCR under various abiotic stress conditions (drought, salt, heat, and cold), and we found that most TaBES1-like genes were downregulated under abiotic stress, particularly during drought stress. We therefore used drought-tolerant and drought-sensitive wheat cultivars to explore TaBES1 expression patterns under drought stress. TaBES1-3B2 and TaBES1-3D2 expression was high in drought-tolerant cultivars but substantially repressed in drought-sensitive cultivars, while TaBES1-6D presented an opposite pattern. Among genes preferentially expressed in anthers, TaBES1-3B2 and TaBES1-3D2 expression was substantially downregulated in thermosensitive genic male-sterile wheat lines compared to common wheat cultivar under sterile conditions, while we detected no obvious differences under fertile conditions. This result suggests that TaBES1-3B2 and TaBES1-3D2 might not only play roles in regulating drought tolerance, but also participate in low temperature-induced male sterility.

Phyto-microbiome to mitigate abiotic stress in crop plants.

Plant-associated microbes include taxonomically diverse communities of bacteria, archaebacteria, fungi, and viruses, which establish integral ecological relationships with the host plant and constitute the phyto-microbiome. The phyto-microbiome not only contributes in normal growth and development of plants but also plays a vital role in the maintenance of plant homeostasis during abiotic stress conditions. Owing to its immense metabolic potential, the phyto-microbiome provides the host plant with the capability to mitigate the abiotic stress through various mechanisms like production of antioxidants, plant growth hormones, bioactive compounds, detoxification of harmful chemicals and toxins, sequestration of reactive oxygen species and other free radicals. A deeper understanding of the structure and functions of the phyto-microbiome and the complex mechanisms of phyto-microbiome mediated abiotic stress mitigation would enable its utilization for abiotic stress alleviation of crop plants and development of stress-resistant crops. This review aims at exploring the potential of phyto-microbiome to alleviate drought, heat, salinity and heavy metal stress in crop plants and finding sustainable solutions to enhance the agricultural productivity. The mechanistic insights into the role of phytomicrobiome in imparting abiotic stress tolerance to plants have been summarized, that would be helpful in the development of novel bioinoculants. The high-throughput modern approaches involving candidate gene identification and target gene modification such as genomics, metagenomics, transcriptomics, metabolomics, and phyto-microbiome based genetic engineering have been discussed in wake of the ever-increasing demand of climate resilient crop plants.

Linking the role of melatonin in plant stress acclimatization

Melatonin is a derivative of tryptophan and consists of a conserved domain present ubiquitously from bacteria to higher organisms. Melatonin is an emerging pleiotropic plant growth hormone that is pivotal in coping with various biotic and abiotic stress conditions. It regulates downstream signaling transduction that modulates plants' physiological and biochemical pathways. Melatonin can be externally applied and could strengthen the stress tolerance mechanism of plants by enhancing ROS-scavenging enzymatic and non-enzymatic antioxidant defense systems. Which consequently exhibits lower lipid peroxidation, MDA content, greater enzyme activity, metabolic pool, ion homeostasis, and plasma membrane integrity under stress conditions. In addition, melatonin protects photosynthetic machinery by maintaining cell membrane stability and chlorophyll recovery. It also stimulates the electron transport chain during photosynthesis and D1 protein biosynthesis and maximizes the photochemistry efficiency (Fv/Fm) of photosystem II and photochemical quenching. Besides abiotic stress, melatonin plays a significant role in biotic stress tolerance. This review emphasizes Melatonin as a stress protectant under biotic and abiotic stress. Further, we have highlighted integrating advanced biotechnology tools with recent information for the possible application of melatonin in the current scenario of changing climate.

Genome-wide identification of KCS gene family in Carya illinoinensis and their roles under abiotic stress conditions

Pecan (Carya illinoinensis) is an important economic tree species of genus Carya in the Juglandaceae. Its nuts are rich in nutrients, becoming one of the consumer's favorite ones. The pecan production is facing serious threats from drought, soil salinization and acidification. β-Keto-acyl-CoA synthase (KCS) is an important enzyme responsible for the formation of very long chain fatty acid (VLCFA) and its derivatives. However, the characteristic of CiKCS genes family in pecan and their function under abiotic stress remain greatly unknown. Here, 30 CiKCSs were identified and distributed in the 14 chromosomes, subjected to gene duplication and strong purification selection. The cis-regulatory elements in the 2 kb promoters of these CiKCSs mainly correlated with plant growth, development and stress response. Notably, CiKCS3/4/5/6/24/28 genes expressions were significantly up-regulated under drought, salt and acid stresses. Interestingly, the expression of CiKCS12 under acid stress were down-regulated. CiKCS3/5/6/12 were further shown to be mainly located in the cytoplasm, had no self-activation activity and could not interact with each other. Heterologous expression of these four genes improved VLCFA levels in tobacco and mediated the tolerance of yeast to osmotic, salt, and acid treatments. These results preliminarily suggested that CiKCS3/5/6/12 might function in the cytoplasm through monomeric forms and improve the tolerance of pecan to abiotic stress mainly by mediating VLCFA synthesis. These findings will deepen the understanding of the characteristic and function of CiKCS genes, and provide new direction and reference for the stress-resistant breeding of pecan.

Apoplastic barriers of Populus × canescens roots in reaction to different cultivation conditions and abiotic stress treatments

Populus is an important tree genus frequently cultivated for economical purposes. However, the high sensitivity of poplars towards water deficit, drought, and salt accumulation significantly affects plant productivity and limits biomass yield. Various cultivation and abiotic stress conditions have been described to significantly induce the formation of apoplastic barriers (Casparian bands and suberin lamellae) in roots of different monocotyledonous crop species. Thus, this study aimed to investigate to which degree the roots of the dicotyledonous gray poplar (Populus × canescens) react to a set of selected cultivation conditions (hydroponics, aeroponics, or soil) and abiotic stress treatments (abscisic acid, oxygen deficiency) because a differing stress response could potentially help in explaining the observed higher stress susceptibility. The apoplastic barriers of poplar roots cultivated in different environments were analyzed by means of histochemistry and gas chromatography and compared to the available literature on monocotyledonous crop species. Overall, dicotyledonous poplar roots showed only a remarkably low induction or enhancement of apoplastic barriers in response to the different cultivation conditions and abiotic stress treatments. The genetic optimization (e.g., overexpression of biosynthesis key genes) of the apoplastic barrier development in poplar roots might result in more stress-tolerant cultivars in the future.

Catalase Gene Family in Durum Wheat: Genome-Wide Analysis and Expression Profiling in Response to Multiple Abiotic Stress Conditions.

Catalase (CAT) is an antioxidant enzyme expressed by the CAT gene family and exists in almost all aerobic organisms. In fact, the CAT enzyme modulates the hydrogen peroxide (H2O2) contents in cells by translating this toxic compound into water (H2O) and O2- to reduce reactive oxygen species (ROS) contents in cells. ROS are produced as a result of biotic and abiotic environmental stressors. To avoid ROS toxicity, plants are armed with different enzymatic and non-enzymatic systems to decompose ROS. Among the enzymatic system, CAT proteins are well studied. CAT not only controls growth and development in plants but is also involved in plant defense against different stresses. So far, the CAT gene family has not been reported in durum wheat (Triticum turgidum ssp. durum L.). Therefore, a genome-wide comprehensive analysis was conducted to classify the CAT genes in the durum wheat genome. Here, six TdCAT genes were identified. Based on phylogenetics, the TdCAT genes belong to three groups (Groups I-III) which is explainable by their comparable structural characteristics. Using bio-informatic analysis, we found that the secondary and tertiary structures were conserved among plants and present similar structures among durum wheat CATs. Two conserved domains (pfam00199 and pfam06628) are also present in all identified proteins, which have different subcellular localizations: peroxisome and mitochondrion. By analyzing their promoters, different cis-elements were identified, such as hormone-correlated response and stress-related responsive elements. Finally, we studied the expression pattern of two catalase genes belonging to two different sub-classes under different abiotic stresses. Expression profiling revealed that TdCAT2 and TdCAT3 presented a constitutive expression pattern. Moreover, both genes are induced in response to salt, mannitol, cold, heat and ABA. Thus, we speculate that those genes are activated by different stresses, such as oxygen deficiency, light, cold, abscisic acid and methyl jasmonate. Further, this study will help in understanding the behavior of CAT genes during environmental stress in durum wheat and in Triticeae species in general.

Multiple Ways of Nitric Oxide Production in Plants and Its Functional Activity under Abiotic Stress Conditions.

Nitric oxide (NO) is an endogenous signaling molecule that plays an important role in plant ontogenesis and responses to different stresses. The most widespread abiotic stress factors limiting significantly plant growth and crop yield are drought, salinity, hypo-, hyperthermia, and an excess of heavy metal (HM) ions. Data on the accumulation of endogenous NO under stress factors and on the alleviation of their negative effects under exogenous NO treatments indicate the perspectives of its practical application to improve stress resistance and plant productivity. This requires fundamental knowledge of the NO metabolism and the mechanisms of its biological action in plants. NO generation occurs in plants by two main alternative mechanisms: oxidative or reductive, in spontaneous or enzymatic reactions. NO participates in plant development by controlling the processes of seed germination, vegetative growth, morphogenesis, flower transition, fruit ripening, and senescence. Under stressful conditions, NO contributes to antioxidant protection, osmotic adjustment, normalization of water balance, regulation of cellular ion homeostasis, maintenance of photosynthetic reactions, and growth processes of plants. NO can exert regulative action by inducing posttranslational modifications (PTMs) of proteins changing the activity of different enzymes or transcriptional factors, modulating the expression of huge amounts of genes, including those related to stress tolerance. This review summarizes the current data concerning molecular mechanisms of NO production and its activity in plants during regulation of their life cycle and adaptation to drought, salinity, temperature stress, and HM ions.

Salicylic acid restricts mercury translocation by activating strong antioxidant defense mechanisms in sweet pepper (Capsicum annum L.)

Mercury (Hg) availability in soil and its absorption in plants is seriously concerned for plant production and human health. Salicylic acid (SA) is one of the major plant hormones involved in plant growth and development under biotic and abiotic stress conditions. So, the experiment was designed to assess the effect of SA on sweet pepper (Capsicum annum L.) seedlings grown under different Hg toxicity concentrations. Spraying of 100 μM SA at three different Hg levels, i.e., 0 μM, 50 μM, 100 μM, and 150 μM. The maximum decrease in photosynthetic machinery, plant growth attributes (shoot length, root length, no. of leaves, fresh and dry biomass (shoot and root)), and more accumulation of Hg in leaves, roots, and fruits of sweet pepper. Additionally, SA significantly reduced the reduction in photosynthetic attributes and plant growth, and increased antioxidant enzymes (SOD, POD, and CAT) under Hg toxicity. H2O2 was found to be lower in plants treated with SA under Hg toxicity than in non-treated plants. The SA application also restricts the accumulation of Hg in sweet pepper roots, leaves, and fruits. Hg translocation in leaves and fruits was also reduced under SA. These findings provide a novel perspective on Hg accumulation in sweet pepper. They open a door to identify SA signaling pathways to clarify the mechanisms of SA inhibiting Hg accumulation in leaves and fruits.

The current scenario and future perspectives of transgenic oilseed mustard by CRISPR-Cas9.

Production of a designer crop having added attributes is the primary goal of all plant biotechnologists. Specifically, development of a crop with a simple biotechnological approach and at a rapid pace is most desirable. Genetic engineering enables us to displace genes among species. The newly incorporated foreign gene(s) in the host genome can create a new trait(s) by regulating the genotypes and/or phenotypes. The advent of the CRISPR-Cas9 tools has enabled the modification of a plant genome easily by introducing mutation or replacing genomic fragment. Oilseed mustard varieties (e.g., Brassica juncea, Brassica nigra, Brassica napus, and Brassica carinata) are one such plants, which have been transformed with different genes isolated from the wide range of species. Current reports proved that the yield and value of oilseed mustard has been tremendously improved by the introduction of stably inherited new traits such as insect and herbicide resistance. However, the genetic transformation of oilseed mustard remains incompetent due to lack of potential plant transformation systems. To solve numerous complications involved in genetically modified oilseed mustard crop varieties regeneration procedures, scientific research is being conducted to rectify the unwanted complications. Thus, this study provides a broader overview of the present status of new traits introduced in each mentioned varieties of oilseed mustard plant by different genetical engineering tools, especially CRISPR-Cas9, which will be useful to improve the transformation system of oilseed mustard crop plants. This review presents recent improvements made in oilseed mustard genetic engineering methodologies by using CRISPR-Cas9 tools, present status of new traits introduced in oilseed mustard plant varieties. The review highlighted that the transgenic oilseed mustard production is a challenging process and the transgenic varieties of oilseed mustard provide a powerful tool for enhanced mustard yield. Over expression studies and silencing of desired genes provide functional importance of genes involved in mustard growth and development under different biotic and abiotic stress conditions. Thus, it can be expected that in near future CRISPR can contribute enormously in improving the mustard plant's architecture and develop stress resilient oilseed mustard plant species.

Screening for native Trichoderma strains as potential biocontrollers of the olive pathogen Verticillium dahliae

Verticillium dahliae is a soilborne pathogen that causes significant losses in olive crops in northwestern Argentina. Biological control through antagonistic microorganisms such as Trichoderma has great potential in the management of Verticillium wilt of olive. This investigation aims to isolate, identify and characterize native Trichoderma strains for biocontrol of V. dahliae. Thirty-nine Trichoderma strains were isolated from soils of olive orchards and natural areas and they were morphologically and molecularly characterized. Desired attributes for plant growth and bioprotection, such as indole acetic acid (IAA) production, endophytism and antagonistic potential against the pathogen were evaluated. Thirteen Trichoderma species were identified, belonging to the Trichoderma, Longibrachiatum, Virens, and Harzianum clades. Physiological characterization revealed that fourteen strains produced IAA while ten showed endophytic capacity. The antagonistic parameters quantified were very variable: eight strains showed high growth inhibition values (PI > 65%), while six strains reached mycoparasitism (PM) values higher than 90% for both pathogens. Three endophytic strains exhibited IAA production and antagonistic activity against V. dahliae, becoming potential candidates for bioprotection of olive orchards. Olive cultivation in the arid regions of northwestern Argentina is subjected to strong stress conditions mainly due to the type of soils with low organic matter content and water retention. Thus, selected Trichoderma strains with more than one beneficial attribute are a fundamental tool for sustainable olive cultivation, not only as antagonists of emerging pathogens but also as mitigators of abiotic stress conditions that prevail in these environments.

Current understanding of unlocking the power of melatonin and other phytohormones to boost abiotic stress tolerance in solanaceous vegetable crops

Solanaceous vegetable crops are extensively consumed and cultivated around the world, however they are often subjected towards different abiotic stress conditions including cold, heat, drought, salt and heavy-metals toxicity. These stresses notably affect plant growth, yield, and quality. Novel Phytohormones plays a major role in managing crop responses to abiotic stress conditions, particularly those seen in Solanaceous vegetable crops. In this review, an overview of the physiological, morphological and molecular responses of Solanaceous vegetable crops to abiotic stresses, and the regulatory roles of the novel phytohormones in these responses, is furnished. Furthermore, the impact of abiotic stresses on the biosynthesis, metabolism and signaling pathways of major phytohormones, particularly melatonin (MEL), salicylic-acid (SA), jasmonic-acid (JA), strigolactones (SLs), brassinosteroids (BRs) and gamma-aminobutyric acid (GABA) is discussed. Consequently, phytohormones application remarkably boosts growth status of plant, leaf photosynthetic apparatus, root architecture system, osmolytes accumulation, and secondary metabolites production, and upregulates photosynthesis related gene expression. In addition, phytohormone regulates ascorbate-glutathione cycle and reduces cellular membrane damage, as well as maintains mineral nutrient homeostasis. Overall, the current review delivers a comprehensive overview of the recent studies on regulating roles of phytohormones for abiotic stresses in Solanaceous vegetables crops, which may serve as a valuable resource for researchers and breeders working for the enhancement of crop resilience and productivity in challenging environments.

Straw Mulch Induced Indoleamines Alleviate Reproductive Depression in Cold Sensitive Hazelnut Cultivars.

Climate change is forcing physiological changes, especially in temperate trees, in which the reproduction phase has been affected harshly, eventually resulting in poor performance. Erratic fluctuations during the flowering periods, predominantly in cold-sensitive, yet industry-desired (sourced), hazelnut cultivars have been causing at least a 10-fold decline in the nut yield. Indoleamines have been noted to provide protection during such abiotic stress conditions. In this study, we investigated the potential involvement of the indoleamine pathway in countering reproductive depression in cold-sensitive hazelnuts by blanketing the ground with wheat straw mulch. The female flower ratio; titers of tryptophan, serotonin, and melatonin; and indoleamine pathway gene regulation were the endpoints for assessing the effects of straw mulch. In the preceding year, we noted that the occurrence of phenological events through the modulation of indoleamines was necessitated via percolation of snowmelt into the rootzone. Otherwise, reproductive depression was noted, especially in harsh conditions, such as 'no snow' or when the rootzone was covered with a plastic sheet to disallow water percolation. When cold-sensitive hazelnut cultivars that were subjected to such deleterious treatments in the preceding years' experiments were treated with straw mulch, the female flower ratio was unaffected and remained on par with that of the cold-hardy locally adapted cultivars. Tryptophan accumulation improved in the (cold-sensitive) sourced cultivars treated with straw mulch and was available as serotonin to counter the cold stress. Lower titers of melatonin explained the slight improvement in female ratio in the sourced cultivars blanketed with straw mulch. ASMT gene regulation via straw mulch treatment emphasized its role in abiotic stress mitigation. A negative trend was noted when improved flowering was compared to the decreased expression of the ASMT gene. Horticultural changes, such as mulch, should provide mitigating solutions to relieve reproductive depression in cold-sensitive hazelnuts, alongside implications in other horticultural crops. The indoleamine toolkit (cellular markers) developed in this study provides insights into the mechanisms of cold sensitivity (abiotic stress) and plausible solutions, such as exogenous application of indoleamines, to propagate climate resilient plant materials with an enhanced capacity to mitigate abiotic stress conditions.

Plant dehydrins and dehydrin-like proteins: characterization and participation in abiotic stress response.

Abiotic stress has a significant impact on plant growth and development. It causes changes in the subcellular organelles, which, due to their stress sensitivity, can be affected. Cellular components involved in the abiotic stress response include dehydrins, widely distributed proteins forming a class II of late embryogenesis abundant protein family with characteristic properties including the presence of evolutionarily conserved sequence motifs (including lysine-rich K-segment, N-terminal Y-segment, and often phosphorylated S motif) and high hydrophilicity and disordered structure in the unbound state. Selected dehydrins and few poorly characterized dehydrin-like proteins participate in cellular stress acclimation and are also shown to interact with organelles. Through their functioning in stabilizing biological membranes and binding reactive oxygen species, dehydrins and dehydrin-like proteins contribute to the protection of fragile organellar structures under adverse conditions. Our review characterizes the participation of plant dehydrins and dehydrin-like proteins (including some organellar proteins) in plant acclimation to diverse abiotic stress conditions and summarizes recent updates on their structure (the identification of dehydrin less conserved motifs), classification (new proposed subclasses), tissue- and developmentally specific accumulation, and key cellular activities (including organellar protection under stress acclimation). Recent findings on the subcellular localization (with emphasis on the mitochondria and plastids) and prospective applications of dehydrins and dehydrin-like proteins in functional studies to alleviate the harmful stress consequences by means of plant genetic engineering and a genome editing strategy are also discussed.

Enchanting Insights and Exploring the Relevance of the Magic Population in Advancing Cereal Crop Improvement

Multiparent Advanced Generation Inter-cross Populations (MAGIC) populations are portrayed as inbred recombinant sets that were created by inter-crossing certain numerous parents. However it takes a lot of work to produce MAGIC populations but Its more effective approach for detecting QTL’s (Quantitative Trait Loci) when we involves MAGIC populations. The availability of more genetic variety in the germplasms due to various founder lines is one of the main benefits of employing a MAGIC population. In order to identify QTL’s for crop improvement under biotic and abiotic stress conditions, MAGIC populations were developed for the indica and japonica rice cultivars as well as MAGIC plus and Global MAGIC populations. Also the employment of MAGIC populations for the improvement of rice grain size also improves the yield and quality aspects of rice. Utilization of rice MAGIC plus populations for the improvement of nutrient profile of rice which is prime important in the biofortification program of rice as a goal of united nations. Where the utilization of association mapping and MAGIC populations in maize crop for improving saccharification efficiency results in higher biofuel production. Various institutes and universities are involved in production of MAGIC populations in respective specialised crops. This article gives the idea of MAGIC populations and their applications in different and diverse applications for the ultimate benefit of yield improvement.