Nitrogen deficiency-induced decrease in cytokinins content promotes rice seminal root growth by promoting root meristem cell proliferation and cell elongation
作者单位：College of Plant Science and Technology Huazhong Agricultural University National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University
会议名称：《第十九届中国作物学会学术年会》
会议日期：2020年
关 键 词：cell elongation cell proliferation cytokinin nitrogen deficiency root meristem seminal root growth
摘 要：Rice (Oryza sativa L.) is one of the most important food crops in the *** the past 50 years,rice yield has steadily increased worldwide,partly owing to an increase in nitrogen (N) ***,at present,the average recovery efficiency of N fertilizer is only 33%at the field *** N input and low N use efficiency not only increase crop production costs but also cause severe environmental ***,decreasing N application is an important goal of sustainable ***,decreasing N application may lead to N deficiency and affect rice root growth,and the underlying mechanism by which N deficiency affects rice root growth is still poorly *** growth is influenced by several external and internal factors,including N availability and phytohormone *** evidences suggest that both N and cytokinin (CK) are involved in mediating root growth,however,the interaction mechanism between N and CK underlying this developmental plasticity is still poorly *** rice Nipponbare (Oryza sativa L.)was used in this *** seeds were sterilized,soaked and germinated,then the germinated rice seeds were grown in an artificial climate incubator with a 12-h light (29℃)/12-h dark (26℃) *** this study,the influence of N deficiency on CK metabolism in rice seminal roots was ***,the mechanism by which N and CK interact to regulate rice seminal root growth was *** results demonstrate that N deficiency reduces CK content by inhibiting CK biosynthesis and promoting CK degradation through down-regulation of CK biosynthesis genes and up-regulation of CK degradation genes,***,our results indicate that the N deficiency-induced decrease in CK content promotes rice seminal root growth not only by enhancing root meristem cell proliferation rate through increased root meristem cell number,but also by promoting root cell elongation through up-regulation of root-specific Os