Phloem Unloading in Developing Rice Caryopses and its Contribution to Non-Structural Carbohydrate Translocation from Stems and Grain Yield Formation

文献类型： 外文期刊

第一作者： Li, Guohui

作者： Li, Guohui;Cui, Kehui;Hu, Qiuqian;Wang, Wencheng;Pan, Junfeng;Zhang, Guo;Shi, Yange;Nie, Lixiao;Huang, Jianliang;Peng, Shaobing;Li, Guohui;Pan, Junfeng;Nie, Lixiao

作者机构：

关键词： Cell wall invertase; Non-structural carbohydrates; Plasmodesma; Rice (Oryza sativa L; ); Sucrose transporter; Symplasmic and apoplasmic unloading

期刊名称：PLANT AND CELL PHYSIOLOGY （ 影响因子：4.937； 五年影响因子：5.783 ）

ISSN： 0032-0781

年卷期： 2022 年 63 卷 10 期

页码：

收录情况： SCI

摘要： Phloem unloading plays an important role in photoassimilate partitioning and grain yield improvements in cereal crops. The phloem unloading strategy and its effects on photoassimilate translocation and yield formation remain unclear in rice. In this study, plasmodesmata were observed at the interface between the sieve elements (SEs) and companion cells (CCs), and between the SE-CC complex and surrounding parenchyma cells (PCs) in phloem of the dorsal vascular bundle in developing caryopses. Carboxyfluorescein (CF) signal was detected in the phloem of caryopses, which showed that CF was unloaded into caryopses. These results indicated that the SE-CC complex was symplasmically connected with adjacent PCs by plasmodesmata. Gene expression for sucrose transporter (SUT) and cell wall invertase (CWI), and OsSUT1 and OsCIN1 proteins were detected in developing caryopses, indicating that rice plants might actively unload sucrose into caryopses by the apoplasmic pathway. Among three rice recombinant inbred lines, R201 exhibited lower plasmodesmal densities at the boundaries between cell types (SE-CC, SE-PC and CC-PC) in developing caryopses than R91 and R156. R201 also had lower expression of SUT and CWI genes and lower protein levels of OsSUT1 and OsCIN1, as well as CWI activity, than R91 and R156. These data agreed with stem non-structural carbohydrate (NSC) translocation and grain yields for the three lines. The nitrogen application rate had no significant effect on plasmodesmal densities at the interfaces between different cells types, and did not affect CF unloading in the phloem of developing caryopses. Low nitrogen treatment enhanced expression levels of OsSUT and OsCIN genes in the three lines. These results suggested that nitrogen application had no substantial effect on symplasmic unloading but affected apoplasmic unloading. Therefore, we concluded that poor symplasmic and apoplasmic unloading in developing caryopses might result in low stem NSC translocation and poor grain yield formation of R201.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序