Tre6P(trehalose-6-phosphate)mediates sensing of carbon availability to maintain sugar homeostasis in plants,which underpins crop yield and resilience.However,how Tre6P responds to fluctuations in sugar levels and regu...Tre6P(trehalose-6-phosphate)mediates sensing of carbon availability to maintain sugar homeostasis in plants,which underpins crop yield and resilience.However,how Tre6P responds to fluctuations in sugar levels and regulates the utilization of sugars for growth remains to be addressed.Here,we report that the sugar-inducible rice NAC transcription factor OsNAC23 directly represses the transcription of the Tre6P phosphatase gene TPP1 to simultaneously elevate Tre6P and repress trehalose levels,thus facilitating carbon partitioning from source to sink organs.Meanwhile,OsNAC23 and Tre6P suppress the transcription and enzyme activity of SnRK1a,a low-carbon sensor and antagonist of OsNAC23,to prevent the SnRK1a-mediated phosphorylation and degradation of OsNAC23.Thus,OsNAC23,Tre6P,and SnRK1a form a feed-forward loop to sense sugar and maintain sugar homeostasis by transporting sugars to sink organs.Importantly,plants over-expressing OsNAC23 exhibited an elevated photosynthetic rate,sugar transport,and sink organ size,which consistently increased rice yields by 13%–17%in three elite-variety backgrounds and two locations,suggesting that manipulation of OsNAC23 expression has great potential for rice improvement.Collectively,these findings enhance our understanding of Tre6P-mediated sugar signaling and homeostasis,and provide a new strategy for genetic improvement of rice and possibly also other crops.展开更多
基金supported by National Key R&D Program of China(2020YFE0202300)CNRRI Key Research and Development Project(CNRRI-2020-01)+1 种基金National Natural Science Foundation of China(Grant grant no.32071986 and 31871229)ASTIP program of CAAS,China.All the authors declare no conflicts of interests in this paper.
文摘Tre6P(trehalose-6-phosphate)mediates sensing of carbon availability to maintain sugar homeostasis in plants,which underpins crop yield and resilience.However,how Tre6P responds to fluctuations in sugar levels and regulates the utilization of sugars for growth remains to be addressed.Here,we report that the sugar-inducible rice NAC transcription factor OsNAC23 directly represses the transcription of the Tre6P phosphatase gene TPP1 to simultaneously elevate Tre6P and repress trehalose levels,thus facilitating carbon partitioning from source to sink organs.Meanwhile,OsNAC23 and Tre6P suppress the transcription and enzyme activity of SnRK1a,a low-carbon sensor and antagonist of OsNAC23,to prevent the SnRK1a-mediated phosphorylation and degradation of OsNAC23.Thus,OsNAC23,Tre6P,and SnRK1a form a feed-forward loop to sense sugar and maintain sugar homeostasis by transporting sugars to sink organs.Importantly,plants over-expressing OsNAC23 exhibited an elevated photosynthetic rate,sugar transport,and sink organ size,which consistently increased rice yields by 13%–17%in three elite-variety backgrounds and two locations,suggesting that manipulation of OsNAC23 expression has great potential for rice improvement.Collectively,these findings enhance our understanding of Tre6P-mediated sugar signaling and homeostasis,and provide a new strategy for genetic improvement of rice and possibly also other crops.
