Journal of Plant Pathology & Microbiology

Water stress induced nitrogen redistribution to root improves nitrogen use efficiency at the vegetative stage of rice (Oryza sativa L.)

3^rd International Conference on Plant Science & Physiology

May 21-22, 2018 Osaka, Japan

Qianyu Jin, Chu Zhong and Cao Xiaochuang

China National Rice Research Institute, China

Posters & Accepted Abstracts: J Plant Pathol Microbiol

Abstract:

N can be easily transported from old organs to developing organs for reutilization. N remobilization between organs is important for high nitrogen use efficiency (NUE) at whole-plant level. Two hybrid rice cultivars japonica â??Yongyou 538â?? and indica â??Zhongzhou 1â?? were hydroponically cultivated at low N (LN, 0.71 mM) and sufficient N (SN, 2.86 mM). The imposition of water stress, which was induced by 100 g.L-1 PEG 6000, resulted in an increase of NUE in â??Yongyou 538â??, but a reduction in â??Zhongzhou 1â??. Water stress reduced nitrate and ammonium uptake and accumulation in â??Yongyou 538â??, whereas nitrate and ammonium uptake in â??Zhongzhou 1â?? was not significantly affected. Contrary to â??Yongyou 538â??, â??Zhongzhou 1â?? accumulated more ammonium in roots under water stress. In addition, water stress caused an increase in catabolism of carbon in roots of â??Zhongzhou 1â??, as indicated by increased root activity, constant pyruvate kinase activity and sucrose concentration and reduced total carbon. The degradation of protein was also augmented in â??Zhongzhou 1â??. In contrast, the consumption of assimilates in â??Yongyou 538â?? was significantly inhibited, allowing more carbon stored in roots. Furthermore, water stress resulted in a significant increase in N allocation in root at SN. NUE was positive correlated with the percentage of N allocated in roots (r=0.723, n=32, p<0.01), but negatively correlated with the percentage of N allocated in leaves (r=-0.756, n=32, p<0.01). The results indicate that attenuation of root catabolic activity under water stress reduces nitrogen uptake and enhances the accumulation of carbon and nitrogen in roots, subsequently improves NUE at whole-plant level.

Biography :

Qianyu Jin has his expertise in rice high yield, mechanized cultivation technology and nitrogen utilization. Recently, he studies the rice productivity and economic benefit of triple cropping systems in paddy field in northern Zhejiang plain and also investigates the mechanisms of drought resistance in different rice varieties and specific expression of QTL for related agronomic characters under water Stress.
Email:11014041@zju.edu.cn