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Hu B.,CAS Institute of Genetics and Developmental Biology | Wang W.,CAS Institute of Genetics and Developmental Biology | Wang W.,University of Chinese Academy of Sciences | Ou S.,CAS Institute of Genetics and Developmental Biology | And 21 more authors.
Nature Genetics

Asian cultivated rice (Oryza sativa L.) consists of two main subspecies, indica and japonica. Indica has higher nitrate-absorption activity than japonica, but the molecular mechanisms underlying that activity remain elusive. Here we show that variation in a nitrate-transporter gene, NRT1.1B (OsNPF6.5), may contribute to this divergence in nitrate use. Phylogenetic analysis revealed that NRT1.1B diverges between indica and japonica. NRT1.1B-indica variation was associated with enhanced nitrate uptake and root-to-shoot transport and upregulated expression of nitrate-responsive genes. The selection signature of NRT1.1B-indica suggests that nitrate-use divergence occurred during rice domestication. Notably, field tests with near-isogenic and transgenic lines confirmed that the japonica variety carrying the NRT1.1B-indica allele had significantly improved grain yield and nitrogen-use efficiency (NUE) compared to the variety without that allele. Our results show that variation in NRT1.1B largely explains nitrate-use divergence between indica and japonica and that NRT1.1B-indica can potentially improve the NUE of japonica. © 2015 Nature America, Inc. All rights reserved. Source

Wang X.,Yangtze University | Wang Y.,Yangtze University | Tian X.,Yangtze University | Ma G.,Yangtze University | Ma G.,China National Hybrid Rice Research and Development Center
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering

To elucidate the effects of NMUrea on the N runoff losses characteristics and nitrogen use efficiency, the experiment was carried out and the nitrogen concentration, nitrogen runoff losses character, and grain yield were studied, with common Urea as control(CK). The results showed that total nitrogen (TN) concentration increased sharply after nitrogen fertilizer application. At the same nitrogen rate, the TN concentration in the NMUrea treatments decreased significantly faster than those of the normal Urea. Based on a logarithm model, the safe drainage time was 11.5-15.9 d after nitrogen application for NMUrea and 12.5-17.3 d after nitrogen application for Urea, respectively. The amount of N loss from drainage increased with the increase of nitrogen fertilizer rate. At the same N fertilizer rate, N loss in NMUrea treatment was less than that in the Urea treatment, and that was 70.6%-74.3% of Urea's. It was also indicated that grain yield and N agronomic efficiency of NMUrea treatment were higher than those of Urea treatments. On the above basis, it was concluded that NMUrea treatments gained higher grain yield and N agronomic efficiency, and lower N loss compared with the normal Urea treatments. The treatment with 225 kg/hm2 NMUrea-N was recommended as the best rate for achieving high-yield, high-N efficiency and safe cultivation technique in hybrid rice. Source

Wang H.,Chinese University of Hong Kong | Chen J.,Chinese University of Hong Kong | Lin H.,Chinese University of Hong Kong | Yuan D.,China National Hybrid Rice Research and Development Center
Remote Sensing Letters

The objective of this study is to validate the effectiveness of hyperspectral data and select hyperspectral variables to indicate differences between the non-transgenic parent and the progenies of transgenic rice regardless of gene expression. Statistically significant differences were observed in the range 510-735 nm. More differences could be observed from first-order derivative than from the original reflectance spectra. Spectral position- and index-based variables were calculated to find out the potential indicators. Both the maximum value of first-order derivative and the sum of first-order derivative in the ranges 490-530 and 560-650 nm, photochemical reflectance index (PRI) and modified chlorophyll absorption ratio index (MCARI) were different between parent group and progeny groups of transgenic rice. Source

Zou H.,Yangtze University | Zou H.,Chinese Academy of Agricultural Sciences | Li C.,Yangtze University | Liu H.,Chinese Academy of Agricultural Sciences | And 4 more authors.
Australian Journal of Crop Science

SnRK2s play a key role in the plant stress signaling transduction pathway. In previous study, ZmSPK1, a SnRK2 member has been cloned from maize. Expression pattern analyses showed that ZmSPK1 is induced by mannitol, salt and ABA. To investigate its role under stresses, in this study, ZmSPK1 was subcloned into the plant expression vector pGreen0029 under control of the cauliflower mosaic virus 35S promoter and transferred into Arabidopsis by Agrobacterium tumefaciens. When treated with salt, compared to wild type, transgenic Arabidopsis grow better, have higher seedling fresh weight (FW) and dry weight (DW), proline content and superoxide dismutase (SOD) activity; whereas, malondialdehyde (MDA) content and the relative electric conductivity of transgenic plants are kept to a relative lower level. Our results suggest that ZmSPK1 may play an important role in salt resistance. Source

Zou H.,Yangtze University | Tian X.,Yangtze University | Ma G.,China National Hybrid Rice Research and Development Center | Zhao M.,Yangtze University | And 2 more authors.
Australian Journal of Crop Science

Studies have shown that Pto (confers resistance to Pseudomonas syringae pv. tomato) plays an important role in plant disease resistance pathway. However, little is known about its responses to salt stress. A previous study has shown that maize ZmPto (Pto-like gene from Zea mays L.) is induced by salicylic acid (SA), abscisic acid (ABA), mannitol and salt. In this study, ZmPto was over-expressed in Arabidopsis in order to further analyze its biological functions. Under salt stress, transgenic plants grew better, had significantly higher seedling fresh and dry weight (FW, DW), seed yields, proline content and lower relative electric conductivity level compared with wild type. The seedling FW of transgenic lines, L1 and L2, increased by 40% and 60%, respectively. In addition, the DW of transgenic lines seedling, L1 and L2, increased 45% and 53%, respectively. The seed weight of L1 and L2 transgenic lines increased 73 % and 120 %, respectively. Semi-quantitative RT-PCR revealed that compared with the wide type (WT) plants, the expression levels of RD29B, KIN2, SOS3 and P5CS1 in transgenic lines increased significantly. To our knowledge, this is the first report from the effect of over-expression of Pto-like gene which enhances the salt resistance in plants. Source

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