异源表达csp2基因提高玉米苗期耐盐性

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Heterologous Expression of the csp2 Gene Enhances the Salt Tolerance of Maize Seedling

WANG Guoxu，XU Yiwei，ZHANG Yingying，LI Rui，LI Jian，CHEN Yuxin， HANXinyun，PENG Yunling'，ZHENGJun （'College ofAgronomy，GansuAgricultural University/KeyLaboratoryofCrop ScienceinArid Habitats，GansuProvince/ KeyLaboratoryofCropGeneticImprovementandGermplasm Innovation，GansuProvince，Lanzhou730o;InstituteofCrop Sciences，ChineseAcademy ofAgricultural Sciences，Beijing）

Abstract： Maize （Zea mays L.） is one of the most important crops for both human consumption and livestock feed，but its growth and yield are seriously constrained by salt stress.Therefore，developing salttolerant maize varieties is crucial for sustainable agriculture.In this study，we characterized the salt tolerance phenotypes and physiological responses in csp2-overexpressing transgenic lines （csp2oE） within the CAL genetic background at the seedling stage. Compared to CAL，the csp2oE lines exhibited significantly higher survival rates，reduced malondialdehyde （MDA）and hydrogen peroxide （H2O2） ）levels，enhanced catalase（CAT） activity and proline content.Additionally，the csp2OE lines showed lower Na+ content and Na+/K+ ratio in shoots，confirming that csp2 overexpression enhances salt stress tolerance.To further investigate the possible molecular mechanism of the csp2 gene under salt stress，the transcriptome sequencing was performed on CAL and the csp2oE-72 line under both control conditions and 12h of salt stress treatment. Differentially expressed genes （DEGs）were primarily enriched in the cell periphery，metabolic pathways，and plant hormone signal transduction，particularly the abscisic acid （ABA） response，starch and sucrose metabolism，and amino acid transmembrane transport. These findings demonstrate the significant role of csp2 in maize salt tolerance and suggest its potential for genetic improvement of salt-tolerant maize varieties.

Keywords：transgenic maize;csp2 gene;salt tolerance;transcriptome analysis

近年来，作物遭受干旱、高盐、冷害、冻害等非生物胁迫造成的产量下降已成为限制全球农业发展的重要因素，其中盐胁迫是导致作物产量下降的重要因素之一[1]。（剩余19685字）