OsDOF11 Affects Nitrogen Metabolism by Sucrose Transport Signaling in Rice (Oryza sativa L.).

Xinglei Huang,Leilei Wang,Min Jiang,Xinyi Dong,Weixin Hu,Fei Xiong,Yunfei Wu,Gynheung An,Gang Chen,Yiyan Zhang

doi:10.3389/fpls.2021.703034

Xinglei Huang, Leilei Wang + Show 8 more

Open Access

https://doi.org/10.3389/fpls.2021.703034

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Abstract

Carbon and nitrogen antagonistically regulate multiple developmental processes. However, the molecular mechanism affecting nitrogen metabolism by sucrose transport remains poorly defined. Previously, we noted that Oryza sativa DNA BINDING WITH ONE FINGER 11 (OsDOF11) mediated sucrose transport by binding to the promoter regions of Sucrose Transporter 1 (SUT1), Oryza sativa Sugars Will Eventually be Exported Transporters 11 (OsSWEET11), and OsSWEET14. Here, we note that OsDOF11 promotes nitrogen uptake and then maintains the ratio of fresh weight to dry weight in seedling plants and the effective leaf blade at flowering stages. Mutants of the sucrose transporter gene OsSWEET14 displayed a phenotype similar to that of OsDOF11. By microarray analysis and qRT-PCR in OsDOF11 mutant plants, OsDOF11 affected the transcription level of amino acid metabolism-related genes. We further found that mainly amino acid contents were reduced in flag leaves but increased in seeds. Both sugar and organic nitrogen changes caused the ratio of fresh weight to dry weight to decrease in OsDOF11 mutant seedling plants and mature leaves, which might result in vigorous reduced metabolic activity and become less susceptible to stress. These results demonstrated that OsDOF11 affected nitrogen metabolism by sugar distribution in rice, which provided new insight that OsDOF11 coordinated with C and N balance to maintain plant growth activity.

Highlights

Rice (Oryza sativa L.) is one of the most important crops for over one-third of the population of the world (Sasaki and Burr, 2000)
We found that the effective leaf blades of OsDOF11 mutants had lower N content under different nitrogen treatments (Figure 2A)
We further studied the responses of N metabolism to sucrose, aiming to characterize physiological responses and metabolic pathways associated with the carbon distribution in OsDOF11 mutant and RNA interference (RNAi)-9 rice plants

Summary

Introduction

Rice (Oryza sativa L.) is one of the most important crops for over one-third of the population of the world (Sasaki and Burr, 2000). An increase in photosynthetic rate or a higher nitrogen use efficiency in plants and crops might be a vital element to resolve the food crisis. Sucrose is synthesized in mesophyll cells and moves from source tissue into sink tissue cells via a phloem loading system to support plant growth and development (Ayre, 2011). Sucrose phloem loading systems contain two traditional sucrose transport routes, apoplastic loading and symplastic loading (Braun et al, 2014). Two membrane protein family genes, SUT (Sucrose Transporter, called SUC for Sucrose Carrier) and SWEETs (Sugars Will Eventually be Exported Transporters)-type transporter, participate in apoplastic loading between CC and SE, except for plasmodesmata (Braun et al, 2014; Wu et al, 2018)

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