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Progress in the regulation of apical stem cell maintenance and root growth by jasmonic acid

As an important plant hormone, jasmonic acid regulates plant resistance to insect invasion, pathogen infection and mechanical injury, and many aspects of plant growth and development at the same time. Around 1980s, it has been recognized that jasmonic acid inhibits plant growth, but the cytology and molecular mechanism of jasmonic acid to achieve this physiological function are not clear yet.

The team, led by Li Chuanyou, a researcher at the institute of genetics and developmental biology, Chinese academy of sciences, found that jasmonic acid inhibits the growth of the root of arabidopsis thaliana by affecting cell division and elongation. At the same time, jasmonic acid altered the cytological structure of the root tip stem cell microenvironment, including causing abnormal division of stationary center (QC) cells and abnormal differentiation of root cap stem cells, and resulted in decreased activity of root meristem. These cytological changes induced by jasmonic acid are similar to the phenotypes caused by mutations in the auxin-pathway stem cell transcription factor gene PLETHORA (PLT). Gel blocking, chromatin immunoprecipitation and other molecular biological experiments showed that MYC2, an important transcription factor of the jasmonic acid signaling pathway, directly binds to the promoter of plt1/2 and inhibits its expression.

Because auxin way by raising expression positive regulation of PLT root stem cells maintain and root meristem activity, and this study found that jasmonic acid maintain and root meristem activity by reducing PLT expression and negative regulation root stem cells , so the work reveals the jasmonic acid and auxin antagonism interactions regulating root stem cells maintain and taproot growth mechanisms. This work suggests that the coordination of growth and development processes through the interaction of different hormone signals may be a universal mechanism for plant responses to the environment formed in the course of long-term evolution.

The researches were published online September 28 in The international journal The Plant Cell. Chen qianhe, a doctoral candidate in li chuanyou's laboratory, and sun jiangqiang, an associate researcher, are co-first authors of the paper. The research was funded by the ministry of science and technology and the national natural science foundation of China.
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