Functional Study on OsMAPK5 Gene Regulating Rice Plant Height and Spike Development

Liu Zeyun; Zhou Jieqiang; Chen Wenjuan; Dong Yating; Wang Shujie; Zhang Junbo; Yu Qiang; Tang Wenbang; Xiao Yunhua

doi:10.14083/j.issn.1001-4942.2025.08.002

Abstract：The MAPK(mitogen-activated protein kinase)signaling pathway is an important signaling mechanism widely present in eukaryotes,which regulates the physiological response of cells to external stimuli through gradually activating three key protein kinase families,MAPKKK,MAPKK and MAPK by phosphoryl-ation.In order to study the function of OsMAPK5(accession number:LOC_Os03g17700)gene in rice,we created the OsMAPK5 gene knockout mutants and overexpression materials by CRISPR/Cas9 gene editing and transgenic technology.The results of phenotypic identification at maturity showed that the OsMAPK5 gene could dwarf the plant height of rice,and the loss of OsMAPK5 gene function was achieved by inhibiting the panicle length and the inverted internode length,while the overexpression of OsMAPK5 gene was achieved by inhibi-ting the length of panicle and the first and second inverted internodes.Further studies showed that OsMAPK5 also affected panicle development and seed setting in rice,and overexpression of OsMAPK5 gene significantly reduced the number of primary branches,secondary branches,grains per panicle and seed setting rate.How-ever,the loss of OsMAPK5 function had no significant effect on panicle development,but significantly reduced the seed setting rate.In conclusion,the OsMAPK5 gene had the function of dwarfing rice plant height,and af-fected panicle development and seed setting,which would be helpful to further improve the molecular regula-tion mechanism of rice plant height and provide gene resources for breeding.