Unveiling the sweetness: evaluating yield and quality attributes of early generation sweet corn (Zea mays subsp. sachharata) inbred lines through morphological, biochemical and marker-based approaches.

BACKGROUND: Sweet corn is gaining tremendous demand worldwide due to urbanization and changing consumer preferences. However, genetic improvement in this crop is being limited by narrow genetic base and other undesirable agronomic traits that hinder the development of superior cultivars. The main requirement in this direction is the development of potentially promising parental lines. One of the most important strategies in this direction is to develop such lines from hybrid-oriented source germplasm which may provide diverse base material with desirable biochemical and agro-morphological attributes. METHODS AND RESULTS: The study was undertaken to carry out morphological and biochemical evaluation of 80 early generation inbred lines (S2) of sweet corn that were developed from a cross between two single cross sweet corn hybrids (Mithas and Sugar-75). Moreover, validation of favourable recessive alleles for sugar content was carried out using SSR markers. The 80 sweet corn inbreds evaluated for phenotypic characterization showed wide range of variability with respect to different traits studied. The highest content of total carotenoids was found in the inbred S27 (34 µg g-1) followed by the inbred S65 (31.1 µg g-1). The highest content for total sugars was found in S60 (8.54%) followed by S14 (8.34%). Molecular characterization of 80 inbred lines led to the identification of seven inbreds viz., S21, S28, S47, S48, S49, S53, and S54, carrying the alleles specific to the sugary gene (su1) with respect to the markers umc2061 and bnlg1937. Comparing the results of scatter plot for biochemical and morphological traits, it was revealed that inbreds S9, S23, S27 and S36 contain high levels of total sugars and total carotenoids along with moderate values for amylose and yield attributing traits. CONCLUSION: The inbred lines identified with desirable biochemical and agro-morphological attributes in the study could be utilized as source of favourable alleles in sweet corn breeding programmes after further validation for disease resistance and other agronomic traits. Consequently, the study will not only enhance the genetic base of sweet corn germplasm but also has the potential to develop high-yielding hybrids with improved quality. The inbreds possessing su1 gene on the basis of umc2061 and bnlg1937 markers were also found to possess high sugar content. This indicates the potential of these lines as desirable candidates for breeding programs aimed at improving sweet corn yield and quality. These findings also demonstrate the effectiveness of the molecular markers in facilitating marker-assisted selection for important traits in sweet corn breeding.

Genome-wide association studies: an intuitive solution for SNP identification and gene mapping in trees.

Analysis of natural diversity in wild/cultivated plants can be used to understand the genetic basis for plant breeding programs. Recent advancements in DNA sequencing have expanded the possibilities for genetically altering essential features. There have been several recently disclosed statistical genetic methods for discovering the genes impacting target qualities. One of these useful methods is the genome-wide association study (GWAS), which effectively identifies candidate genes for a variety of plant properties by examining the relationship between a molecular marker (such as SNP) and a target trait. Conventional QTL mapping with highly structured populations has major limitations. The limited number of recombination events results in poor resolution for quantitative traits. Only two alleles at any given locus can be studied simultaneously. Conventional mapping approach fails to work in perennial plants and vegetatively propagated crops. These limitations are sidestepped by association mapping or GWAS. The flexibility of GWAS comes from the fact that the individuals being examined need not be linked to one another, allowing for the use of all meiotic and recombination events to increase resolution. Phenotyping, genotyping, population structure analysis, kinship analysis, and marker-trait association analysis are the fundamental phases of GWAS. With the rapid development of sequencing technologies and computational methods, GWAS is becoming a potent tool for identifying the natural variations that underlie complex characteristics in crops. The use of high-throughput sequencing technologies along with genotyping approaches like genotyping-by-sequencing (GBS) and restriction site associated DNA (RAD) sequencing may be highly useful in fast-forward mapping approach like GWAS. Breeders may use GWAS to quickly unravel the genomes through QTL and association mapping by taking advantage of natural variances. The drawbacks of conventional linkage mapping can be successfully overcome with the use of high-resolution mapping and the inclusion of multiple alleles in GWAS.

Evaluating genetic diversity of geographically diverse populations of Embelia ribes Burm f., a highly medicinal woody liana from the Western Ghats of India, using random amplified polymorphic DNA (RAPD) and intersimple sequence repeats (ISSR) markers.

BACKGROUND: Embelia ribes Burm f. (Primulaceae) is a medicinal and vulnerable woody liana distributed throughout India. Embelin, a well-recognized active phytoconstituents in berries, is commonly used in ayurvedic formulations. Due to over-exploitation, the status of the plant is vulnerable. Previous studies on this species mainly focused on its phytochemical analysis, which led to overexploitation and loss of the germplasm. METHODS AND RESULTS: In the present study, 20 RAPD and 18 ISSR markers were employed to assess genetic divergence in 40 genotypes of E. ribes collected from different parts of the Western Ghats of India. In RAPD analysis, all 40 accessions with 20 RAPD primers amplified 282 fragments, with 83.91% average polymorphism and with an average of 14.10 bands per primer. The size of amplicons varied from 200 to 2500 bp. While, ISSR primers produced 203 fragments of which 161 were polymorphic with an average of 11.28 bands per primer with 73.25% average polymorphism. The size of amplicons ranges from 200 to 2500 bp. RAPD and ISSR markers were also assessed by calculating polymorphic information content (PIC) to discriminate the genotypes; the average PIC value for RAPD, ISSR, and combined RAPD + ISSR markers obtained was more than 0.50 suggesting the informativeness of markers. UPGMA analysis based on Jaccard's similarity coefficient for RAPD, ISSR, and RAPD + ISSR data reveals that 40 accessions of E. ribes were depicted in four clusters. The clustering pattern of all individuals in PCoA analysis agreed with the UPGMA dendrograms, which further confirms the genetic relationships explained by cluster analysis. AMOVA analysis of RAPD, ISSR, and combined marker system revealed variation within the population, ranging from 41 to 44%, and among the population, it ranged from 56 to 59%. CONCLUSION: The present study provides an optimized method for evaluating the genetic diversity of Embelia ribes using RAPD and ISSR markers which are useful for further sustainable utilization and conservation of natural populations in the Western Ghats of India.

Multi-omics assisted breeding for biotic stress resistance in soybean.

Biotic stress is a critical factor limiting soybean growth and development. Soybean responses to biotic stresses such as insects, nematodes, fungal, bacterial, and viral pathogens are governed by complex regulatory and defense mechanisms. Next-generation sequencing has availed research techniques and strategies in genomics and post-genomics. This review summarizes the available information on marker resources, quantitative trait loci, and marker-trait associations involved in regulating biotic stress responses in soybean. We discuss the differential expression of related genes and proteins reported in different transcriptomics and proteomics studies and the role of signaling pathways and metabolites reported in metabolomic studies. Recent advances in omics technologies offer opportunities to reshape and improve biotic stress resistance in soybean by altering gene regulation and/or other regulatory networks. We suggest using 'integrated omics' to precisely understand how soybean responds to different biotic stresses. We also discuss the potential challenges of integrating multi-omics for the functional analysis of genes and their regulatory networks and the development of biotic stress-resistant cultivars. This review will help direct soybean breeding programs to develop resistance against different biotic stresses.

Orphan legumes: harnessing their potential for food, nutritional and health security through genetic approaches.

Legumes, being angiosperm's third-largest family as well as the second major crop family, contributes beyond 33% of human dietary proteins. The advent of the global food crisis owing to major climatic concerns leads to nutritional deprivation, hunger and hidden hunger especially in developing and underdeveloped nations. Hence, in the wake of promoting sustainable agriculture and nutritional security, apart from the popular legumes, the inclusion of lesser-known and understudied local crop legumes called orphan legumes in the farming systems of various tropical and sub-tropical parts of the world is indeed a need of the hour. Despite possessing tremendous potentialities, wide adaptability under diverse environmental conditions, and rich in nutritional and nutraceutical values, these species are still in a neglected and devalued state. Therefore, a major re-focusing of legume genetics, genomics, and biology is much crucial in pursuance of understanding the yield constraints, and endorsing underutilized legume breeding programs. Varying degrees of importance to these crops do exist among researchers of developing countries in establishing the role of orphan legumes as future crops. Under such circumstances, this article assembles a comprehensive note on the necessity of promoting these crops for further investigations and sustainable legume production, the exploitation of various orphan legume species and their potencies. In addition, an attempt has been made to highlight various novel genetic, molecular, and omics approaches for the improvement of such legumes for enhancing yield, minimizing the level of several anti-nutritional factors, and imparting biotic and abiotic stress tolerance. A significant genetic enhancement through extensive research in 'omics' areas is the absolute necessity to transform them into befitting candidates for large-scale popularization around the globe.

Improving Zinc and Iron Biofortification in Wheat through Genomics Approaches.

Globally, about 20% of calories (energy) come from wheat. In some countries, it is more than 70%. More than 2 billion people are at risk for zinc deficiency and even more, people are at risk of iron deficiency, nearly a quarter of all children underage group of 5 are physically and cognitively stunted, and lack of dietary zinc is a major contributing factor. Biofortified wheat with elevated levels of zinc and iron has several potential advantages as a delivery vehicle for micronutrients in the diets of resource-poor consumers who depend on cereal-based diets. The conventional breeding strategies have been successful in the introduction of novel alleles for grain Zn and Fe that led to the release of competitive Zn enriched wheat varieties in South Asia. The major challenge over the next few decades will be to maintain the rates of genetic gains for grain yield along with increased grain Zn/Fe concentration to meet the food and nutritional security challenges. Therefore, to remain competitive, the performance of Zn-enhanced lines/varieties must be equal or superior to that of current non-biofortified elite lines/varieties. Since both yield and Zn content are invisible and quantitatively inherited traits except few intermediate effect QTL regions identified for grain Zn, increased breeding efforts and new approaches are required to combine them at high frequency, ensuring that Zn levels are steadily increased to the required levels across the breeding pipelines. The current review article provides a comprehensive list of genomic regions for enhancing grain Zn and Fe concentrations in wheat including key candidate gene families such NAS, ZIP, VLT, ZIFL, and YSL. Implementing forward breeding by taking advantage of the rapid cycling trait pipeline approaches would simultaneously introgress high Zn and Fe QTL into the high Zn and normal elite lines, further increasing Zn and Fe concentrations.

Back to the wild: mining maize (Zea mays L.) disease resistance using advanced breeding tools.

Cultivated modern maize (Zea mays L.) originated through the continuous process of domestication from its wild progenitors. Today, maize is considered as the most important cereal crop which is extensively cultivated in all parts of the world. Maize shows remarkable genotypic and phenotypic diversity which makes it an ideal model species for crop genetic research. However, intensive breeding and artificial selection of desired agronomic traits greatly narrow down the genetic bases of maize. This reduction in genetic diversity among cultivated maize led to increase the chance of more attack of biotic stress as climate changes hampering the maize grain production globally. Maize germplasm requires to integrate both durable multiple-diseases and multiple insect-pathogen resistance through tapping the unexplored resources of maize landraces. Revisiting the landraces seed banks will provide effective opportunities to transfer the resistant genes into the modern cultivars. Here, we describe the maize domestication process and discuss the unique genes from wild progenitors which potentially can be utilized for disease resistant in maize. We also focus on the genetics and disease resistance mechanism of various genes against maize biotic stresses and then considered the different molecular breeding tools for gene transfer and advanced high resolution mapping for gene pyramiding in maize lines. At last, we provide an insight for targeting identified key genes through CRISPR/Cas9 genome editing system to enhance the maize resilience towards biotic stress.

Wheat spike blast: genetic interventions for effective management.

The fundamental concepts of the genetics, race classification and epidemiology of the Wheat spike blast causing fungus Magnaporthe oryzae pathotype Triticum (MoT) are still evolving despite of its discovery in 1985 in Brazil for the first time. The fungus seems to defy the research progress that is being made globally by continuously evolving into pathotypes which have already overcome the much celebrated 2NS resistance in wheat lines as well as few of the initially effective fungicides. The compartmentalized i.e. two speed genome of the MoT, conferring the fungus an evolutionary advantage, has emerged as a challenge for the wheat spike blast researchers complicating its already difficult management. The airborne fungus with a range of alternative hosts is finding new geographical niches situated on different continents and is a matter of great apprehension among the nations whose food security is primarily dependent on wheat. The wheat blast outbreak in Bangladesh during 2016 was attributed to an isolate from Latin America escaping through a seed import consignment while the latest Zambian outbreak is still to be studied in detail regarding its origin and entry. The challenges in dealing wheat spike blast are not only on the level of genetics and epidemiology alone but also on the levels of policy making regarding international seed movement and research collaborations. The present review deals with these issues mainly concerning the effective management and controlling the international spread of this deadly disease of wheat, with a particular reference to India. We describe the origin, taxonomy, epidemiology and symptomology of MoT and briefly highlight its impact and management practices from different countries. We also discuss the advances in genomics and genome editing technologies that can be used to develop elite wheat genotypes resistant against different stains of wheat spike blast.

Juvenile heat stress tolerance in Triticum durum-Aegilops tauschii derived synthetics: a way forward for wheat improvement.

BACKGROUND: Exponentially increasing population and everchanging climatic conditions are two major concerns for global food security. Early sowing in the second fortnight of October is an emerging trend with farmers in Indo Gangetic Plains to avoid yield losses from terminal heat stress. This also benefits the use of residual soil moisture of rice crop, conserving about one irrigation. But most of the available wheat cultivars are not well adapted to early-season sowing. METHODS AND RESULTS: Two in-house developed SHWs, syn14128 and syn14170, were screened for juvenile heat stress. Seedling length, biochemical parameters, and expression of amylase gene immediately after heat shock (HS) of 45 °C for 12 h and 20 h, and 24 h indicated significantly lower malondialdehyde, hydrogen peroxide, and higher free radical scavenging activities. Syn14170 reported higher total soluble sugar (TSS) under both HS periods, while syn14128 had a sustainable TSS content and amylase activity under HS as well as the recovery period. CONCLUSIONS: Both the SHWs had lower oxidative damage along with high free radical scavenging under heat stress. The higher expression of amy4 along with sustainable TSS after heat stress in syn14128 indicated it as a potential source of juvenile heat stress tolerance. Variable response of SHWs to different biochemical parameters under heat stress opens future perspectives to explore the enzymatic pathways underlying these responses.

Narrowing down molecular targets for improving phosphorus-use efficiency in maize (Zea mays L.).

Conventional agricultural practices rely heavily on chemical fertilizers to boost production. Among the fertilizers, phosphatic fertilizers are copiously used to ameliorate low-phosphate availability in the soil. However, phosphorus-use efficiency (PUE) for major cereals, including maize, is less than 30%; resulting in more than half of the applied phosphate being lost to the environment. Rock phosphate reserves are finite and predicted to exhaust in near future with the current rate of consumption. Thus, the dependence of modern agriculture on phosphatic fertilizers poses major food security and sustainability challenges. Strategies to optimize and improve PUE, like genetic interventions to develop high PUE cultivars, could have a major impact in this area. Here, we present the current understanding and recent advances in the biological phenomenon of phosphate uptake, translocation, and adaptive responses of plants under phosphate deficiency, with special reference to maize. Maize is one of the most important cereal crops that is cultivated globally under diverse agro-climatic conditions. It is an industrial, feed and food crop with multifarious uses and a fast-rising global demand and consumption. The interesting aspects of diversity in the root system architecture traits, the interplay between signaling pathways contributing to PUE, and an in-depth discussion on promising candidate genes for improving PUE in maize are elaborated.

CRISPR/Cas tool designs for multiplex genome editing and its applications in developing biotic and abiotic stress-resistant crop plants.

Crop plants are prone to several yield-reducing biotic and abiotic stresses. The crop yield reductions due to these stresses need addressing to maintain an adequate balance between the increasing world population and food production to avoid food scarcities in the future. It is impossible to increase the area under food crops proportionately to meet the rising food demand. In such an adverse scenario overcoming the biotic and abiotic stresses through biotechnological interventions may serve as a boon to help meet the globe's food requirements. Under the current genomic era, the wide availability of genomic resources and genome editing technologies such as Transcription Activator-Like Effector Nucleases (TALENs), Zinc Finger Nucleases (ZFNs), and Clustered-Regularly Interspaced Palindromic Repeats/CRISPR-associated proteins (CRISPR/Cas) has widened the scope of overcoming these stresses for several food crops. These techniques have made gene editing more manageable and accessible with changes at the embryo level by adding or deleting DNA sequences of the target gene(s) from the genome. The CRISPR construct consists of a single guide RNA having complementarity with the nucleotide fragments of the target gene sequence, accompanied by a protospacer adjacent motif. The target sequence in the organism's genome is then cleaved by the Cas9 endonuclease for obtaining a desired trait of interest. The current review describes the components, mechanisms, and types of CRISPR/Cas techniques and how this technology has helped to functionally characterize genes associated with various biotic and abiotic stresses in a target organism. This review also summarizes the application of CRISPR/Cas technology targeting these stresses in crops through knocking down/out of associated genes.

Chlorophyll fluorescence and grain filling characteristic of wheat (Triticum aestivum L.) in response to nitrogen application level.

BACKGROUND: This study aims to understand the influence of chlorophyll fluorescence parameters on yield of winter wheat in some areas of China. Nitrogen (N) application is believed to improve photosynthesis in flag leaf ultimately increase final yield. METHODS AND RESULTS: To understand the response of chlorophyll fluorescence parameters of wheat, flag leaf and the effect of N fertilization was carried out at booting stage under greenhouse during year 2018-2019 using winter wheat cultivar "Yunhan-20410' 'Yunhan-618". The results showed that the maximum chlorophyll content of flag leaves occurred at booting stage. Under, Yunhan-20410 condition, maximum photochemical quantum efficiency (FV/Fm), potential activity (ΦPSII), potential activity of PSII (FV/FO), and photochemical quenching coefficient (qp) showed "high-low" variation, and the maximum values were observed between May 4 and May 12. However, Yunhan-20410 showed FV/Fm, FV/FO, and qp showed "low-high-low" curve at booting stage. Compared to Yunhan-618, Yunhan-20410 at booting stage significantly decreased FV/Fm, FV/FO, qp, and ΦPSII (P<0.05), and non-photochemical quenching (NPQ) significantly increased (P<0.05). CONCLUSION: The outcome of present investigation suggest that chlorophyll fluorescence parameters could be valuable insight to understand yield stability under stress condition. Moreover, the investigated parameters could be useful criteria for selection of genotypes under varying nitrogen application levels.

Rewilding crops for climate resilience: economic analysis and de novo domestication strategies.

To match predicted population growth, annual food production should be doubled by 2050. This is not achievable by current agronomical and breeding practices, due to the impact of climate changes and associated abiotic stresses on agricultural production systems. Here, we analyze the impact of global climate trends on crop productivity and show that the overall loss in crop production from climate-driven abiotic stresses may exceed US$170 billion year-1 and represents a major threat to global food security. We also show that abiotic stress tolerance had been present in wild progenitors of modern crops but was lost during their domestication. We argue for a major shift in our paradigm of crop breeding, focusing on climate resilience, and call for a broader use of wild relatives as a major tool in this process. We argue that, while molecular tools are currently in place to harness the potential of climate-resilient genes present in wild relatives, the complex polygenic nature of tolerance traits remains a major bottleneck in this process. Future research efforts should be focused not only on finding appropriate wild relatives but also on development of efficient cell-based high-throughput phenotyping platforms allowing assessment of the in planta operation of key genes.

Defensive Mechanisms in Cucurbits against Melon Fly (Bactrocera cucurbitae) Infestation through Excessive Production of Defensive Enzymes and Antioxidants.

Melon fly (Bactrocera cucurbitae) is the most common pest of cucurbits, and it directly causes damage to cucurbit fruits in the early developmental stage. The infection of fruit tissues induces oxidative damage through increased generation of cellular reactive oxygen species. The effects of melon fly infestation on the production of defensive enzymes and antioxidant capabilities in five cucurbit species, namely, bottle gourd, chayote, cucumber, snake gourd, and bitter gourd, were investigated in this study. The total phenolic and flavonoid content was considerably higher in melon fly infestation tissues compared to healthy and apparently healthy tissues. The chayote and bottle gourd tissues expressed almost 1.5- to 2-fold higher phenolic and flavonoid contents compared to the tissues of bitter gourd, snake gourd, and cucumber upon infestation. Defensive enzymes, such as peroxidase (POD), superoxide dismutase (SOD), polyphenol oxidase (PPO), and catalase (CAT), were high in healthy and infected tissues of chayote and bottle gourd compared to bitter gourd, snake gourd, and cucumber. The activity of POD (60-80%), SOD (30-35%), PPO (70-75%), and CAT (40-50%) were high in infected chayote and bottle gourd tissue, representing resistance against infestation, while bitter gourd, snake gourd, and cucumber exhibited comparatively lower activity suggesting susceptibility to melon fly infection. The antioxidant properties were also high in the resistant cucurbits compared to the susceptible cucurbits. The current research has enlightened the importance of redox-regulatory pathways involving ROS neutralization through infection-induced antioxidative enzymes in host cucurbit resistance. The melon fly infestation depicts the possible induction of pathways that upregulate the production of defensive enzymes and antioxidants as a defensive strategy against melon fly infestation in resistant cucurbits.

Secondary Metabolite Profiling, Anti-Inflammatory and Hepatoprotective Activity of Neptunia triquetra (Vahl) Benth.

The present study aimed to analyze the phytoconstituents of Neptunia triquetra (Vahl) Benth. Anti-inflammatory and hepatoprotective activities of ethanol (EE), chloroform (CE) and dichloromethane (DCME) of stem extracts were evaluated using in vivo experimental models. The extracts were analyzed for phytoconstituents using GC-HRMS. Anti-inflammatory activity of CE, EE and DCME was accessed using carrageenan-induced paw oedema, cotton pellet-induced granuloma and the carrageenan-induced air-pouch model in Wistar albino rats. The hepatotoxicity-induced animal models were investigated for the biochemical markers in serum (AST, ALT, ALP, GGT, total lipids and total protein) and liver (total protein, total lipids, GSH and wet liver weight). In the in vivo study, animals were divided into different groups (six in each group) for accessing the anti-inflammatory and hepatoprotective activity, respectively. GC-HRMS analysis revealed the presence of 102 compounds, among which 24 were active secondary metabolites. In vivo anti-inflammatory activity of stem extracts was found in the order: indomethacin > chloroform extract (CE) > dichloromethane extract (DCME) > ethanolic extract (EE), and hepatoprotective activity of stem extracts in the order: CE > silymarin > EE > DCME. The results indicate that N. triquetra stem has a higher hepatoprotective effect than silymarin, however the anti-inflammatory response was in accordance with or lower than indomethacin.

Engineering salinity tolerance in plants: progress and prospects.

MAIN CONCLUSION: There is a need to integrate conceptual framework based on the current understanding of salt stress responses with different approaches for manipulating and improving salt tolerance in crop plants. Soil salinity exerts significant constraints on global crop production, posing a serious challenge for plant breeders and biotechnologists. The classical transgenic approach for enhancing salinity tolerance in plants revolves by boosting endogenous defence mechanisms, often via a single-gene approach, and usually involves the enhanced synthesis of compatible osmolytes, antioxidants, polyamines, maintenance of hormone homeostasis, modification of transporters and/or regulatory proteins, including transcription factors and alternative splicing events. Occasionally, genetic manipulation of regulatory proteins or phytohormone levels confers salinity tolerance, but all these may cause undesired reduction in plant growth and/or yields. In this review, we present and evaluate novel and cutting-edge approaches for engineering salt tolerance in crop plants. First, we cover recent findings regarding the importance of regulatory proteins and transporters, and how they can be used to enhance salt tolerance in crop plants. We also evaluate the importance of halobiomes as a reservoir of genes that can be used for engineering salt tolerance in glycophytic crops. Additionally, the role of microRNAs as critical post-transcriptional regulators in plant adaptive responses to salt stress is reviewed and their use for engineering salt-tolerant crop plants is critically assessed. The potentials of alternative splicing mechanisms and targeted gene-editing technologies in understanding plant salt stress responses and developing salt-tolerant crop plants are also discussed.

QTLian breeding for climate resilience in cereals: progress and prospects.

The ever-rising population of the twenty-first century together with the prevailing challenges, such as deteriorating quality of arable land and water, has placed a big challenge for plant breeders to satisfy human needs for food under erratic weather patterns. Rice, wheat, and maize are the major staple crops consumed globally. Drought, waterlogging, heat, salinity, and mineral toxicity are the key abiotic stresses drastically affecting crop yield. Conventional plant breeding approaches towards abiotic stress tolerance have gained success to limited extent, due to the complex (multigenic) nature of these stresses. Progress in breeding climate-resilient crop plants has gained momentum in the last decade, due to improved understanding of the physiochemical and molecular basis of various stresses. A good number of genes have been characterized for adaptation to various stresses. In the era of novel molecular markers, mapping of QTLs has emerged as viable solution for breeding crops tolerant to abiotic stresses. Therefore, molecular breeding-based development and deployment of high-yielding climate-resilient crop cultivars together with climate-smart agricultural practices can pave the path to enhanced crop yields for smallholder farmers in areas vulnerable to the climate change. Advances in fine mapping and expression studies integrated with cheaper prices offer new avenues for the plant breeders engaged in climate-resilient plant breeding, and thereby, hope persists to ensure food security in the era of climate change.

Salicylic acid enhances nickel stress tolerance by up-regulating antioxidant defense and glyoxalase systems in mustard plants.

The present study identified inverse relationships between nickel (Ni) levels and growth, photosynthesis and physio-biochemical attributes, but increasing levels of Ni stress enhanced methylglyoxal, electrolyte leakage, hydrogen peroxide, and lipid peroxidation content. Exogenous application of salicylic acid (SA) (10-5 M) ameliorated the ill-effects of Ni by restoring growth, photosynthesis and physio-biochemical attributes and increasing the activities of enzymes associated with antioxidant systems, especially the ascorbate-glutathione (AsA-GSH) cycle and glyoxalase system. In addition, SA application to Ni-stressed plants had an additive effect on the activities of the ascorbate and glutathione pools, and the AsA-GSH cycle enzymes (ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase), superoxide dismutase, catalase, glutathione S-transferase, and osmolyte biosynthesis). This trend also follows in glyoxalase system viz. glyoxalase I and glyoxalase II enzymes. Nevertheless, exogenous SA supplementation restored mineral nutrient contents. Principal component analysis showed that growth, photosynthesis, and mineral nutrient parameters were positively correlated with each other and negatively correlated with antioxidant enzymes and oxidative stress biomarkers. Hence, SA is an alternative compound with potential application in the phytoremediation of Ni.

Insights on Calcium-Dependent Protein Kinases (CPKs) Signaling for Abiotic Stress Tolerance in Plants.

Abiotic stresses are the major limiting factors influencing the growth and productivity of plants species. To combat these stresses, plants can modify numerous physiological, biochemical, and molecular processes through cellular and subcellular signaling pathways. Calcium-dependent protein kinases (CDPKs or CPKs) are the unique and key calcium-binding proteins, which act as a sensor for the increase and decrease in the calcium (Ca) concentrations. These Ca flux signals are decrypted and interpreted into the phosphorylation events, which are crucial for signal transduction processes. Several functional and expression studies of different CPKs and their encoding genes validated their versatile role for abiotic stress tolerance in plants. CPKs are indispensable for modulating abiotic stress tolerance through activation and regulation of several genes, transcription factors, enzymes, and ion channels. CPKs have been involved in supporting plant adaptation under drought, salinity, and heat and cold stress environments. Diverse functions of plant CPKs have been reported against various abiotic stresses in numerous research studies. In this review, we have described the evaluated functions of plant CPKs against various abiotic stresses and their role in stress response signaling pathways.