Changes of root characteristics of super hybrid rice variety contributing to high nitrogen accumulation under low nitrogen application at seedling stage
Changes of root characteristics of super hybrid rice variety contributing to high nitrogen accumulation under low nitrogen application at seedling stage
Crop root system plays an important role in nitrogen uptake.In this study,two rice varieties,conventional rice variety Huanghuazhan(HHZ)and super hybrid rice variety Yangliangyou 6(YLY6),were grew hydroponically under high nitrogen(HN)and low nitrogen(LN)treatments to investigate the changes of root characteristics and their relationships with nitrogen accumula-tion at seedling stage.Compared to HN,LN significantly decreased the total N accumulation in HHZ by 19.7％and had no sub-stantial effect in YLY6.Under LN,root dry weight,the total root length,root surface area,and root tips in YLY6 significantly increased by 41.3％,57.1％,74.9％,and 20.6％,respectively.However,these four morphological parameters had no significant change in HHZ.Under LN,root diameter and root cortical area in YLY6 significantly increased by 12.4％and 24.2％,respectively.However,the two parameters and root stele diameter in HHZ significantly reduced by 12.0％,21.9％,and 11.4％,respectively.In YLY6,LN significantly up-regulated the relative expression level of root ammonium transporter genes(AMT2;1,AMT2;3,AMT3;1,and AMT3;2)by 195.6％,29.3％,314.9％,and 388.9％,respectively,and increased the relative expression level of glutamine synthetase gene GS1;1 by 158.2％.However,LN had no effect on the relative expression level of the five genes in HHZ.Total nitrogen accumulation was significantly and positively correlated with the root characteristics(but thickness of root cortical sclerenchyma)and expression of above-mentioned genes under LN.These results indicated that the enhanced positive responses of above-mentioned root characteristics contributed to high nitrogen accumulation in YLY6 seedlings under LN.Developing va-rieties with root positive responses to nitrogen reduction should be a considerable target for green rice production.
维普
万方数据