Development Of Stress-tolerant Crops Research Articles

A Review on Biotechnological Innovations in Developing Stress-Tolerant Crops for Adverse Environmental Conditions

The development of stress-tolerant crops through advanced biotechnological approaches is critical for enhancing global food security and sustainability in the face of climate change and increasing environmental stresses. Emerging tools such as CRISPR/Cas9 gene editing and synthetic biology are revolutionizing genetic engineering by enabling precise, targeted modifications of plant genomes to improve drought, salinity, heat, and cold tolerance. Integrative approaches that combine genomics, transcriptomics, proteomics, and metabolomics provide a comprehensive understanding of plant stress responses, facilitating the identification of key regulatory genes and metabolic pathways. High-throughput phenotyping and RNA interference (RNAi) technologies further enhance trait identification and manipulation, accelerating the development of robust stress-tolerant varieties. The deployment of these crops has demonstrated significant yield improvements and stability in adverse conditions, reducing the risk of crop failures and food shortages. Drought-tolerant maize and rice varieties have increased yields by 20-30% under water-scarce conditions, while salt-tolerant rice and wheat varieties have enabled cultivation in saline soils. Heat-tolerant crops maintain productivity in high-temperature regions, and cold-tolerant varieties extend growing seasons in temperate areas. These advancements not only enhance crop productivity but also promote sustainable agricultural practices by reducing the need for chemical inputs and supporting the resilience of food systems. Moreover, the socio-economic benefits include improved livelihoods for smallholder farmers through increased incomes and economic stability. Continued interdisciplinary research and collaboration are essential to fully realize the potential of these technologies in addressing global agricultural challenges and ensuring a stable food supply for future generations.

AcCIPK5, a pineapple CBL-interacting protein kinase, confers salt, osmotic and cold stress tolerance in transgenic Arabidopsis

Plant-specific calcineurin B-like proteins (CBLs) and their interacting kinases, CBL-interacting protein kinases (CIPKs) module, are essential for dealing with various biotic and abiotic stress. The kinases (CIPKs) of this module have been well studied in several plants; however, the information about pineapple CIPKs remains limited. To understand how CIPKs function against environmental cues in pineapple, the CIPK5 gene of pineapple was cloned and characterized. The phylogenetic analyses revealed that AcCIPK5 is homologous to the CIPK12 of Arabidopsis and other plant species. Quantitative real-time PCR (qRT-PCR) analysis revealed that AcCIPK5 responds to multiple stresses, including osmotic, salt stress, heat and cold. Under optimal conditions, AcCIPK5 gets localized to the cytoplasm and cell membrane. The ectopic expression of AcCIPK5 in Arabidopsis improved the germination under osmotic and salt stress. Furthermore, AcCIPK5 positively regulated osmotic, drought, salt and cold tolerance and negatively regulated heat and fungal stress in Arabidopsis. Besides, the expression of AcCIPK impacted ABA-related genes and ROS homeostasis. Overall, the present study demonstrates that AcCIPK5 contributes to multiple stress tolerance and has the potential to be utilized in the development of stress-tolerant crops.

Delineating Calcium Signaling Machinery in Plants: Tapping the Potential through Functional Genomics.

Plants have developed calcium (Ca2+) signaling as an important mechanism of regulation of stress perception, developmental cues, and responsive gene expression. The post-genomic era has witnessed the successful unravelling of the functional characterization of genes and the creation of large datasets of molecular information. The major elements of Ca2+ signaling machinery include Ca2+ sensors and responders such as Calmodulins (CaMs), Calmodulin-like proteins (CMLs), Ca2+/CaM-dependent protein kinases (CCaMKs), Ca2+-dependent protein kinases (CDPKs), Calcineurin B-like proteins (CBLs) as well as transporters, such as Cyclic nucleotide-gated channels (CNGCs), Glutamate-like receptors (GLRs), Ca2+-ATPases, Ca2+/H+ exchangers (CAXs) and mechanosensitive channels. These elements play an important role in the regulation of physiological processes and plant responses to various stresses. Detailed genomic analysis can help us in the identification of potential molecular targets that can be exploited towards the development of stress-tolerant crops. The information sourced from model systems through omics approaches helps in the prediction and simulation of regulatory networks involved in responses to different stimuli at the molecular and cellular levels. The molecular delineation of Ca2+ signaling pathways could be a stepping stone for engineering climate-resilient crop plants. Here, we review the recent developments in Ca2+ signaling in the context of transport, responses, and adaptations significant for crop improvement through functional genomics approaches.

Characterization and Expression Analysis of Heme Oxygenase Genes from Sorghum bicolor.

Heme oxygenases (HOs) have a major role in phytochrome chromophore biosynthesis, and chromophores in turn have anti-oxidant properties. Plant heme oxygenases are divided into the HO1 sub-family comprising HO1, HO3, and HO4, and the HO2 sub-family, which consists of 1 member, HO2. This study identified and characterized 4 heme oxygenase members from Sorghum bicolor. Multiple sequence alignments showed that the heme oxygenase signature motif (QAFICHFYNI/V) is conserved across all SbHO proteins and that they share above 90% sequence identity with other cereals. Quantitative real-time polymerase chain reaction revealed that SbHO genes were expressed in leaves, stems, and roots, but most importantly their transcript level was induced by osmotic stress, indicating that they might play a role in stress responses. These findings will strengthen our understanding of the role of heme oxygenases in plant stress responses and may contribute to the development of stress tolerant crops.

Analysis of bHLH coding genes of Cicer arietinum during heavy metal stress using biological network.

bHLH family of transcription factors play important role in regulating many cellular and physiological functions in plants. These proteins are also known to be involved in response to several abiotic stress types. Cicer arietinum is an important source of protein in food across the globe. Considerable differential expression in the bHLH family of proteins during heavy metal exposure in Cicer arietinum was observed by microarray data analysis. The study aimed to construct a Pearson coefficient correlation based network of bHLH coding genes in the plant. Microarray data of Cicer arietinum recorded under cadmium and chromium stress (GSE86807) from GEO at NCBI was used for analysis. The network constructed from expression data set of the 85 bHLH coding genes revealed 10 hub genes that are connected with topological genes. These hub genes are stress responsive genes that may also be regarded as the marker genes for heavy metal response. Our analysis reported a new set of reference genes (hub genes) that have potentially significant role in development of stress tolerant crops.

Trehalose Accumulation Triggers Autophagy during Plant Desiccation.

Global climate change, increasingly erratic weather and a burgeoning global population are significant threats to the sustainability of future crop production. There is an urgent need for the development of robust measures that enable crops to withstand the uncertainty of climate change whilst still producing maximum yields. Resurrection plants possess the unique ability to withstand desiccation for prolonged periods, can be restored upon watering and represent great potential for the development of stress tolerant crops. Here, we describe the remarkable stress characteristics of Tripogon loliiformis, an uncharacterised resurrection grass and close relative of the economically important cereals, rice, sorghum, and maize. We show that T. loliiformis survives extreme environmental stress by implementing autophagy to prevent Programmed Cell Death. Notably, we identified a novel role for trehalose in the regulation of autophagy in T.loliiformis. Transcriptome, Gas Chromatography Mass Spectrometry, immunoblotting and confocal microscopy analyses directly linked the accumulation of trehalose with the onset of autophagy in dehydrating and desiccated T. loliiformis shoots. These results were supported in vitro with the observation of autophagosomes in trehalose treated T. loliiformis leaves; autophagosomes were not detected in untreated samples. Presumably, once induced, autophagy promotes desiccation tolerance in T.loliiformis, by removal of cellular toxins to suppress programmed cell death and the recycling of nutrients to delay the onset of senescence. These findings illustrate how resurrection plants manipulate sugar metabolism to promote desiccation tolerance and may provide candidate genes that are potentially useful for the development of stress tolerant crops.

Salinity and drought tolerance conferred by in planta transformation of SNAC1 transcription factor into a high-yielding rice variety of Bangladesh

Abiotic stresses such as drought and high salinity unfavorably affect the growth and productivity of crop plants. Therefore, the development of stress-tolerant crops is essential for the affected cultivable areas. It has been shown in the current study that the overexpression of stress-responsive NAC1 (SNAC1) transcription factor (TF) significantly increases salinity and drought tolerance in a farmer-popular high-yielding, transgenic rice. The indica rice variety BRRIdhan 55, which was poorly responsive to tissue culture was transformed with the SNAC1 TF from the rice landrace Pokkali by the in planta method. Addition of acetosyringone in the Agrobacterium suspension and co-culture media increased previously reported transformation efficiencies by four-folds. Integration of foreign genes into the genome of transgenic plants was confirmed by gene-specific PCR and Southern blot analysis. The level of transgene expression (SNAC1) was also quantified by real-time PCR. Genetic segregation ratio for T1 progenies was calculated and found to follow the law of Mendelian inheritance. Phenotypic screening was conducted at T2 and T3 seedling stages where the transgenic lines exhibited much better tolerance compared to their control non-transgenic plants at 120 mM (NaCl) salt as well as drought stress implemented by withholding water for 20 days.

Abiotic stress QTL in lettuce crop-wild hybrids: comparing greenhouse and field experiments.

The development of stress-tolerant crops is an increasingly important goal of current crop breeding. A higher abiotic stress tolerance could increase the probability of introgression of genes from crops to wild relatives. This is particularly relevant to the discussion on the risks of new GM crops that may be engineered to increase abiotic stress resistance. We investigated abiotic stress QTL in greenhouse and field experiments in which we subjected recombinant inbred lines from a cross between cultivated Lactuca sativa cv. Salinas and its wild relative L. serriola to drought, low nutrients, salt stress, and aboveground competition. Aboveground biomass at the end of the rosette stage was used as a proxy for the performance of plants under a particular stress. We detected a mosaic of abiotic stress QTL over the entire genome with little overlap between QTL from different stresses. The two QTL clusters that were identified reflected general growth rather than specific stress responses and colocated with clusters found in earlier studies for leaf shape and flowering time. Genetic correlations across treatments were often higher among different stress treatments within the same experiment (greenhouse or field), than among the same type of stress applied in different experiments. Moreover, the effects of the field stress treatments were more correlated with those of the greenhouse competition treatments than to those of the other greenhouse stress experiments, suggesting that competition rather than abiotic stress is a major factor in the field. In conclusion, the introgression risk of stress tolerance (trans-)genes under field conditions cannot easily be predicted based on genomic background selection patterns from controlled QTL experiments in greenhouses, especially field data will be needed to assess potential (negative) ecological effects of introgression of these transgenes into wild relatives.

Transcription factor profile analysis of the Antarctic vascular plant Deschampsia antarctica Desv. (Poaceae)

Transcription factors (TFs), which control gene expression through sequence-specific interactions with cis-elements of downstream gene promoters, play an important role in developmental processes and in response to environmental stress. To explore the molecular mechanism behind stress signaling and the development of Antarctic hairgrass (Deschampsia antarctica Desv.), a terrestrial plant that has successfully adapted to the Antarctic climate, we analyzed the D. antarctica EST database and constructed a TF profile based on sequence homology searches with other plant TFs to identify 1,083 transcripts encoding TFs categorized into 53 TF families. The gene ontology distribution of TF-encoding transcripts and lineage-specific expansion/contraction of TF families were analyzed. In addition, we identified a group of putative abiotic stress-induced TFs by comparing EST libraries generated under different abiotic conditions and validated the results using quantitative real-time PCR. Since plant TFs are primary targets for genetic engineering and the development of stress-tolerant crops, these results could be a useful resource for agricultural applications.

Plant growth promoting rhizobacteria for ameliorating abiotic stresses triggered due to climatic variability

The world is gifted with varied landforms and diversity of climatic conditions such as the lofty mountains, the riverine deltas, high altitude forests, peninsular plateaus, variety of geological formations endowed with varying temperature and rainfall. Physical features like temperature, pH, salinity, water content constitute abiotic factors of the ecosystem and if these factors exceed beyond the threshold limit then, they might result in abiotic stresses. Economy of different countries relies on agriculture and abiotic stresses are the major constraints that limit crop productivity around the globe. The development of stress tolerant crops is not an easy and economical approach for sustainable agriculture; however microbial inoculation to alleviate stress tolerance is a better option because it minimizes production costs and environmental hazards.

Regulation of the Arabidopsis thaliana vitamin B 6 biosynthesis genes by abiotic stress

Vitamin B 6 (pyridoxine and its vitamers) plays an essential role as a co-factor for enzymatic reactions and has also recently been implicated in defense against cellular oxidative stress. The biosynthetic pathway was thoroughly characterized in Escherichia coli, however most organisms, including plants, utilize an alternate pathway involving two genes, PDX1 and PDX2. Arabidopsis thaliana contains one copy of PDX2, but three full-length copies of PDX1, one each on chromosomes 2, 3, and 5 (referred to as PDX1.1, PDX1.2, and PDX1.3, respectively). Phylogenetic analysis of the PDX1 homologues in A. thaliana showed that PDX1.1 and PDX1.3 clustered with the homologues from the other dicots, whereas PDX1.2 was more divergent, and did not cluster with either the dicots or monocots. Expression analysis using quantitative PCR showed that PDX1.1 and PDX1.3 were highly expressed in A. thaliana rosettes, while PDX1.2 showed only low level expression. All three PDX1 genes and PDX2 were responsive to abiotic stressors including high light, chilling, drought, and ozone, however, the response of PDX1.2 was disparate from that of the other PDX genes, showing a lessened response to high light, chilling, and drought, but an increased response to ozone. Green fluorescent protein fusion studies demonstrated that PDX2 localizes in the nucleus and membranes of cells, consistent with recent published data for PDX1. Insight into regulation of the biosynthetic genes during abiotic stress could have important applications in the development of stress-tolerant crops.