Knockdown of 60S ribosomal protein L14‑2 reveals their potential regulatory roles to enhance drought and salt tolerance in cotton

Background:Cotton is a valuable economic crop and the main significant source of natural fiber for textile industries globally.The effects of drought and salt stress pose a challenge to strong fiber and large-scale production due to the ever-changing climatic conditions.However,plants have evolved a number of survival strategies,among them is the induction of various stress-responsive genes such as the ribosomal protein large(RPL)gene.The RPL gene families encode critical proteins,which alleviate the effects of drought and salt stress in plants.In this study,comprehensive and functional analysis of the cotton RPL genes was carried out under drought and salt stresses.Results:Based on the genome-wide evaluation,26,8,and 5 proteins containing the RPL14B domain were identified in Gossypium hirsutum,G.raimondii,and G.arboreum,respectively.Furthermore,through bioinformatics analysis,key cis-regulatory elements related to RPL14B genes were discovered.The Myb binding sites(MBS),abscisic acid-responsive element(ABRE),CAAT-box,TATA box,TGACG-motif,and CGTCA-motif responsive to methyl jasmonate,as well as the TCA-motif responsive to salicylic acid,were identified.Expression analysis revealed a key gene,Gh_D01G0234(RPL14B),with significantly higher induction levels was further evaluated through a reverse genetic approach.The knockdown of Gh_D01G0234(RPL14B)significantly affected the performance of cotton seedlings under drought/salt stress conditions,as evidenced by a substantial reduction in various morphological and physiological traits.Moreover,the level of the antioxidant enzyme was significantly reduced in VIGS-plants,while oxidant enzyme levels increased significantly,as demonstrated by the higher malondialdehyde concentration level.Conclusion:The results revealed the potential role of the RPL14B gene in promoting the induction of antioxidant enzymes,which are key in oxidizing the various oxidants.The key pathways need to be investigated and even as we exploit these genes in the developing of more stress-resilient cotton germplasms.

Genome wide identification and characterization of light-harvesting Chloro a/b binding(LHC)genes reveals their potential role in enhancing drought tolerance in Gossypium hirsutum

Background: Cotton is an important commercial crop for being a valuable source of natural fiber.Its production has undergone a sharp decline because of abiotic stresses,etc.Drought is one of the major abiotic stress causing significant yield losses in cotton.However,plants have evolved self-defense mechanisms to cope abiotic factors like drought,salt,cold,etc.The evolution of stress responsive transcription factors such as the trihelix,a nodule-inception-like protein(NLP),and the late embryogenesis abundant proteins have shown positive response in the resistance improvement to several abiotic stresses.Results: Genome wide identification and characterization of the effects of Light-Harvesting Chloro a/b binding(LHC)genes were carried out in cotton under drought stress conditions.A hundred and nine proteins encoded by the LHC genes were found in the cotton genome,with 55,27,and 27 genes found to be distributed in Gossypium hirsutum,G.arboreum,and G.raimondii,respectively.The proteins encoded by the genes were unevenly distributed on various chromosomes.The Ka/Ks(Non-synonymous substitution rate/Synonymous substitution rate)values were less than one,an indication of negative selection of the gene family.Differential expressions of genes showed that majority of the genes are being highly upregulated in the roots as compared with leaves and stem tissues.Most genes were found to be highly expressed in MR-85,a relative drought tolerant germplasm.Conclusion: The results provide proofs of the possible role of the LHC genes in improving drought stress tolerance,and can be explored by cotton breeders in releasing a more drought tolerant cotton varieties.