Unraveling the genetic and molecular basis of heat stress in cotton.

Human activities and climate change have resulted in frequent and intense weather fluctuations, leading to diverse abiotic stresses on crops which hampers greatly their metabolic activities. Heat stress, a prevalent abiotic factor, significantly influences cotton plant biological activities resulting in reducing yield and production. We must deepen our understanding of how plants respond to heat stress across various dimensions, encompassing genes, RNAs, proteins, metabolites for effective cotton breeding. Multi-omics methods, primarily genomics, transcriptomics, proteomics, metabolomics, and phenomics, proves instrumental in studying cotton's responses to abiotic stresses. Integrating genomics, transcriptomics, proteomics, and metabolomic is imperative for our better understanding regarding genetics and molecular basis of heat tolerance in cotton. The current review explores fundamental omics techniques, covering genomics, transcriptomics, proteomics, and metabolomics, to highlight the progress made in cotton omics research.

Microsatellite-based diversity analysis and the development of core-set germplasm in Pakistani barley lines.

Illustrating the population structure and genetic diversity in selected germplasm resources (after three year multi locations trials) plays a key role which directly utilize the selection of lines in a population for accumulative trait breeding in crops. In order to further understand, the structure of population and genetic variability, we explored 100 selected lines, cultivated for three consecutive years (2016-2019) in swat, University of Malakand, Khyber Pakhtunkhwa Pakistan and Provinces of China (Chongqing and Beijing) with 33 mapped SSR markers. The integrated population structure analysis in a core of hundred germplasm with Pakistani origin with three approved commercial barley cultivars have strong stratification that allowed their division into four major subpopulations (i.e. PI, PII, PIII and PIV) and an admixture subpopulation, with 52, 9, 15 and 27 germplasm respectively. A total of 133 alleles were identified with mean value of 0.80 Polymorphic information content. The number of alleles detected by the system varied from two alleles amplified to as six with an average of 4.03 per SSR marker pair. The gene diversity ranged from 0.56 to 0.98 with an average of 0.82 in selected germplasm resources. Based on the SSR data, the 100 selected germplasm with three cultivars were classified into four main phylogenetic Linages (LI, LII, LIII and LIV) which corresponded to the phylogenic grouping in genotypes. We assembled a core set of 20 barley genotypes (~1/5 of original population size) to sustain sufficient mapping of SSR marker with Phenotype, in which we proposed four SSR markers, Bmac0040, Bmac0134, Bmag0125 and Bmag0211 for malt gene and marker (Bmac0399) for tolerance to salinity gene, which will be applicable for marker assisted breeding in barley gene resources.

Drought and heat stress on cotton genotypes suggested agro-physiological and biochemical features for climate resilience.

This study aimed to investigate the impact of individual drought, heat, and combined drought and heat stress on twelve cotton genotypes, including eight tolerant and four susceptible genotypes. A field experiment was carried out by employing a randomized complete block split-plot design, with treatments (control, drought, heat, drought + heat), and cotton genotypes assigned to the main plots and sub-plots respectively. The results showed that the combined stress had a more severe impact on the yield and fiber quality of cotton genotypes compared to individual stresses. Among the studied genotypes, FB-Shaheen, FH-207, MNH-886, and White Gold exhibited superior performance in regard to agronomic and fiber quality characters under combined stress environments. Physiological parameters, including transpiration rate, stomatal conductance, relative water contents, and photosynthetic rate, were significantly reduced under combined stress. However, specific genotypes, MNH-886, FH-207, White Gold, and FB-Shaheen, demonstrated better maintenance of these parameters, indicating their enhanced tolerance to the combined stress. Furthermore, the accumulation of reactive oxygen species was more pronounced under combined stress compared to individual stressors. Tolerant genotypes showed lower levels of H2O2 and MDA accumulation, while susceptible genotypes exhibited higher levels of oxidative damage. Antioxidant enzyme activities, such as superoxide dismutase, peroxidase, and catalase, increased under combined stress, with tolerant genotypes displaying higher enzyme activities. Conversely, susceptible genotypes (AA-703, KZ 191, IR-6, and S-15) demonstrated lower increases in enzymatic activities under combined stress conditions. Biochemical traits, including proline, total phenolic content, flavonoids, and ascorbic acid, exhibited higher levels in resistant genotypes under combined stress, while sensitive genotypes displayed decreased levels of these traits. Additionally, chlorophyll a & b, and carotenoid levels were notably decreased under combined stress, with tolerant genotypes experiencing a lesser decrease compared to susceptible genotypes.

Genomic Dynamics and Functional Insights under Salt Stress in Gossypium hirsutum L.

The changing climate is intensifying salt stress globally. Salt stress is a menace to cotton crop quality and yield. The seedling, germination, and emergence phases are more prone to the effects of salt stress than other stages. Higher levels of salt can lead to delayed flowering, a reduced number of fruiting positions, shedding of fruits, decreased boll weight, and yellowing of fiber, all of which have an adverse effect on the yield and quality of the seed cotton. However, sensitivity toward salt stress is dependent on the salt type, cotton growth phase, and genotype. As the threat of salt stress continues to grow, it is crucial to gain a comprehensive understanding of the mechanisms underlying salt tolerance in plants and to identify potential avenues for enhancing the salt tolerance of cotton. The emergence of marker-assisted selection, in conjunction with next-generation sequencing technologies, has streamlined cotton breeding efforts. This review begins by providing an overview of the causes of salt stress in cotton, as well as the underlying theory of salt tolerance. Subsequently, it summarizes the breeding methods that utilize marker-assisted selection, genomic selection, and techniques for identifying elite salt-tolerant markers in wild species or mutated materials. Finally, novel cotton breeding possibilities based on the approaches stated above are presented and debated.

Breakthrough in CRISPR/Cas system: Current and future directions and challenges.

Targeted genome editing (GE) technology has brought a significant revolution in fictional genomic research and given hope to plant scientists to develop desirable varieties. This technology involves inducing site-specific DNA perturbations that can be repaired through DNA repair pathways. GE products currently include CRISPR-associated nuclease DNA breaks, prime editors generated DNA flaps, single nucleotide-modifications, transposases, and recombinases. The discovery of double-strand breaks, site-specific nucleases (SSNs), and repair mechanisms paved the way for targeted GE, and the first-generation GE tools, ZFNs and TALENs, were successfully utilized in plant GE. However, CRISPR-Cas has now become the preferred tool for GE due to its speed, reliability, and cost-effectiveness. Plant functional genomics has benefited significantly from the widespread use of CRISPR technology for advancements and developments. This review highlights the progress made in CRISPR technology, including multiplex editing, base editing (BE), and prime editing (PE), as well as the challenges and potential delivery mechanisms.

A CRISPR way for accelerating cereal crop improvement: Progress and challenges.

Humans rely heavily on cereal grains as a key source of nutrients, hence regular improvement of cereal crops is essential for ensuring food security. The current food crisis at the global level is due to the rising population and harsh climatic conditions which prompts scientists to develop smart resilient cereal crops to attain food security. Cereal crop improvement in the past generally depended on imprecise methods like random mutagenesis and conventional genetic recombination which results in high off targeting risks. In this context, we have witnessed the application of targeted mutagenesis using versatile CRISPR-Cas systems for cereal crop improvement in sustainable agriculture. Accelerated crop improvement using molecular breeding methods based on CRISPR-Cas genome editing (GE) is an unprecedented tool for plant biotechnology and agriculture. The last decade has shown the fidelity, accuracy, low levels of off-target effects, and the high efficacy of CRISPR technology to induce targeted mutagenesis for the improvement of cereal crops such as wheat, rice, maize, barley, and millets. Since the genomic databases of these cereal crops are available, several modifications using GE technologies have been performed to attain desirable results. This review provides a brief overview of GE technologies and includes an elaborate account of the mechanisms and applications of CRISPR-Cas editing systems to induce targeted mutagenesis in cereal crops for improving the desired traits. Further, we describe recent developments in CRISPR-Cas-based targeted mutagenesis through base editing and prime editing to develop resilient cereal crop plants, possibly providing new dimensions in the field of cereal crop genome editing.

Spermine: Its Emerging Role in Regulating Drought Stress Responses in Plants.

In recent years, research on spermine (Spm) has turned up a lot of new information about this essential polyamine, especially as it is able to counteract damage from abiotic stresses. Spm has been shown to protect plants from a variety of environmental insults, but whether it can prevent the adverse effects of drought has not yet been reported. Drought stress increases endogenous Spm in plants and exogenous application of Spm improves the plants' ability to tolerate drought stress. Spm's role in enhancing antioxidant defense mechanisms, glyoxalase systems, methylglyoxal (MG) detoxification, and creating tolerance for drought-induced oxidative stress is well documented in plants. However, the influences of enzyme activity and osmoregulation on Spm biosynthesis and metabolism are variable. Spm interacts with other molecules like nitric oxide (NO) and phytohormones such as abscisic acid, salicylic acid, brassinosteroids, and ethylene, to coordinate the reactions necessary for developing drought tolerance. This review focuses on the role of Spm in plants under severe drought stress. We have proposed models to explain how Spm interacts with existing defense mechanisms in plants to improve drought tolerance.

Effectiveness of occupational therapy in improving activities of daily living performance in complete cervical tetraplegic patients; A quasi experimental study.

OBJECTIVE: To determine the effectiveness of Occupational therapy (OT) in improving activities of daily living performance in complete cervical tetraplegic patients. METHODS: A quasi experimental study was conducted at Paraplegic Center Peshawar from May 2018 to March 2019. Seventy two spinal cord injury patients with complete cervical tetraplegia having age 18-60 years were included in the study using non probability convenience sampling technique. A trained Occupational therapist conducted two occupational therapy sessions per day, three times a week on alternative days for a period of six weeks. Self-care portion of Spinal cord injury independence measure (SCIM) was used to collect pre and post data. Data was analyzed using SPSS version 20. RESULTS: Mean age of the participants was 30.21±13.52.Majority of the participants were (n= 61, 84.7%) male while remaining 11 (15.3%) participants were female. Pre self-care total score was 0.39±0.987 and post self-care total score was 7.17±5.536. There was significant differences (P value <0.05) between pre and post scores of feeding, upper & lower body bathing, upper & lower body dressing, grooming and total self-care scores. CONCLUSION: Occupational therapy significantly improves activities of daily living performance in complete cervical tetraplegic spinal cord injury patients.