Plants require large amounts of phosphate (Pi) to maintain growth and development. However, Pi is often a limiting factor for plants because of its low availability in the soil, which is mainly due to its low abundance and easy chelation with cations or organic compounds to form insoluble complexes. To cope with Pi starvation, plants have evolved multiple strategies to increase Pi availability. Thus, to reveal the molecular mechanism of Pi starvation responses will provide useful information to develop improved crops with enhanced efficiency of Pi use.

 

Dr. CHU Chengcai’s laboratory (http://chulab.genetics.ac.cn/) from Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, identified the LEAF TIP NECROSIS 1(LTN1) gene which played a pivotal role in regulation of multiple Pi starvation responses in rice. The mutation of LTN1 leads to over-accumulated Pi in the shoots. They also showed that LTN1 regulated Pi uptake and transport by controlling expression of Pi transporter genes. LTN1 was also involved in the regulation of typical Pi starvation responses such as root architecture alteration, stimulation of phosphatase and ribonuclease activities, lipid composition alteration, nitrogen assimilation repression, and increased metal uptake. Moreover, they further proved that LTN1 was down-regulated by OsmiR399. Their results strongly indicated that LTN1 was a crucial Pi starvation signaling component downstream of miR399 involved in the regulation of multiple Pi starvation responses in rice.

 

This work identified the crucial gene in regulation of Pi starvation responses in rice, one of the most important crops in the world. The work not only further revealed the molecular mechanism of Pi starvation responses in rice, but also provided a hint to develop high Pi use efficiency crops. The work appeared on Plant Physiology (online published on February 11, 2011, Doi: 10.1104/pp.110.170209). The Ph.D student HU Bin in the laboratory is the first author of this paper. This research was supported by grants from the Ministry of Science and Technology of China and the National Natural Science Foundation of China.

 

AUTHOR CONTACT:

CHU Chengcai, Ph.D.

Institute of Genetics and Developmetnal Biology, Chinese Academy of Sciences, Beijing, China.