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81.
Wenjing Song Huwei Sun Jiao Li Xianpo Gong Shuangjie Huang Xudong Zhu Yali Zhang Guohua Xu 《Annals of botany》2013,112(7):1383-1393
Background and Aims
Although ammonium (NH4+) is the preferred form of nitrogen over nitrate (NO3−) for rice (Oryza sativa), lateral root (LR) growth in roots is enhanced by partial NO3− nutrition (PNN). The roles of auxin distribution and polar transport in LR formation in response to localized NO3− availability are not known.Methods
Time-course studies in a split-root experimental system were used to investigate LR development patterns, auxin distribution, polar auxin transport and expression of auxin transporter genes in LR zones in response to localized PNN in ‘Nanguang’ and ‘Elio’ rice cultivars, which show high and low responsiveness to NO3−, respectively. Patterns of auxin distribution and the effects of polar auxin transport inhibitors were also examined in DR5::GUS transgenic plants.Key Results
Initiation of LRs was enhanced by PNN after 7 d cultivation in ‘Nanguang’ but not in ‘Elio’. Auxin concentration in the roots of ‘Nanguang’ increased by approx. 24 % after 5 d cultivation with PNN compared with NH4+ as the sole nitrogen source, but no difference was observed in ‘Elio’. More auxin flux into the LR zone in ‘Nanguang’ roots was observed in response to NO3− compared with NH4+ treatment. A greater number of auxin influx and efflux transporter genes showed increased expression in the LR zone in response to PNN in ‘Nanguang’ than in ‘Elio’.Conclusions
The results indicate that higher NO3− responsiveness is associated with greater auxin accumulation in the LR zone and is strongly related to a higher rate of LR initiation in the cultivar ‘Nanguang’. 相似文献82.
83.
Rop在植物生长、发育、免疫及环境信号应答等多种生物学过程中具有重要作用。已有研究显示水稻Rop基因OsRac5可能与育性控制有关,但是该基因的表达特性,以及非生物胁迫和植物生长物质对其表达的影响尚不清楚。本文采用qRT-PCR技术检测了OsRac5在水稻生长发育过程中、非生物胁迫以及植物生长物质处理条件下的表达特性,结果显示OsRac5在水稻生长发育过程中在多种组织广泛表达,尤其在根和雌雄蕊形成期的幼穗中高表达;干旱、高盐和低温等非生物胁迫均能诱导OsRac5表达;ABA、GAs、6-BA等植物生长物质能上调OsRac5基因表达,提示该基因与水稻幼穗发育、抗逆性及细胞生长等过程相关。 相似文献
84.
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86.
Wahyu Indra Duwi Fanata Kyoung Hwan Lee Bo Hwa Son Jae Yong Yoo Rikno Harmoko Ki Seong Ko Nirmal Kumar Ramasamy Kyung Hwa Kim Doo‐Byoung Oh Hyun Suk Jung Jae‐Yean Kim Sang Yeol Lee Kyun Oh Lee 《The Plant journal : for cell and molecular biology》2013,73(6):966-979
To explore the physiological significance of N‐glycan maturation in the plant Golgi apparatus, gnt1, a mutant with loss of N‐acetylglucosaminyltransferase I (GnTI) function, was isolated in Oryza sativa. gnt1 exhibited complete inhibition of N‐glycan maturation and accumulated high‐mannose N‐glycans. Phenotypic analyses revealed that gnt1 shows defective post‐seedling development and incomplete cell wall biosynthesis, leading to symptoms such as failure in tiller formation, brittle leaves, reduced cell wall thickness, and decreased cellulose content. The developmental defects of gnt1 ultimately resulted in early lethality without transition to the reproductive stage. However, callus induced from gnt1 seeds could be maintained for periods, although it exhibited a low proliferation rate, small size, and hypersensitivity to salt stress. Shoot regeneration and dark‐induced leaf senescence assays indicated that the loss of GnTI function results in reduced sensitivity to cytokinin in rice. Reduced expression of A‐type O. sativa response regulators that are rapidly induced by cytokinins in gnt1 confirmed that cytokinin signaling is impaired in the mutant. These results strongly support the proposed involvement of N‐glycan maturation in transport as well as in the function of membrane proteins that are synthesized via the endomembrane system. 相似文献
87.
88.
Bo Kang Zhongchen Zhang Lingling Wang Libin Zheng Weihua Mao Meifei Li Yunrong Wu Ping Wu Xiaorong Mo 《The Plant journal : for cell and molecular biology》2013,74(1):86-97
Auxin plays a pivotal role in many facets of plant development. It acts by inducing the interaction between auxin‐responsive [auxin (AUX)/indole‐3‐acetic acid (IAA)] proteins and the ubiquitin protein ligase SCFTIR to promote the degradation of the AUX/IAA proteins. Other cofactors and chaperones that participate in auxin signaling remain to be identified. Here, we characterized rice (Oryza sativa) plants with mutations in a cyclophilin gene (OsCYP2). cyp2 mutants showed defects in auxin responses and exhibited a variety of auxin‐related growth defects in the root. In cyp2 mutants, lateral root initiation was blocked after nuclear migration but before the first anticlinal division of the pericycle cell. Yeast two‐hybrid and in vitro pull‐down results revealed an association between OsCYP2 and the co‐chaperone Suppressor of G2 allele of skp1 (OsSGT1). Luciferase complementation imaging assays further supported this interaction. Similar to previous findings in an Arabidopsis thaliana SGT1 mutant (atsgt1b), degradation of AUX/IAA proteins was retarded in cyp2 mutants treated with exogenous 1‐naphthylacetic acid. Our results suggest that OsCYP2 participates in auxin signal transduction by interacting with OsSGT1. 相似文献
89.
90.
Yong Yang Fei‐Bo Yu Juan Chen Chu‐Lang Yu Fang Wang Ye Cheng Cheng‐Qi Yan Jian‐Ping Chen 《Journal of Phytopathology》2013,161(5):324-334