Inorganic phosphate(Pi)availability is an important factor which affects the growth and yield of crops,thus an appropriate and effective response to Pi fluctuation is critical.However,how crops orches-trate Pi signaling and growth under Pi starvation conditions to optimize the growth defense tradeoff remains unclear.Here we show that a Pi starvation-induced transcription factor NIGT1(NITRATE-INDUCIBLE GARP-TYPE TRANSCRIPTIONAL RE-PRESSOR 1)controls plant growth and prevents a hyper-response to Pi starvation by directly repressing the expression of growth-related and Pi-signaling genes to achieve a balance between growth and response under a varying Pi environ-ment.NIGT1 directly binds to the promoters of Pi starvation signaling marker genes,like IPS1,miR827,and SPX2,under Pi-deficient conditions to mitigate the Pi-starvation responsive(PSR).It also directly represses the expression of vacuolar Pi efflux transporter genes VPE1/2 to regulate plant Pi ho-meostasis.We further demonstrate that NIGT1 con-strains shoot growth by repressing the expression of growth-related regulatory genes,including brassi-nolide signal transduction master regulator BZR1,cell division regulator CYCB1;1,and DNA replication regulator PSF3.Our findings reveal the function of NIGT1 in orchestrating plant growth and Pi starva-tion signaling,and also provide evidence that NIGT1 acts as a safeguard to avoid hyper-response during Pi starvation stress in rice.

目的 探讨口服葡萄糖耐量试验1h血糖水平在糖代谢中的特点和意义.方法 按糖尿病(DM)诊断标准,将897例PCOS患者分组为:①糖耐量正常组(NGT组);②空腹血糖(FG)受损组(IFG组);③FG正常的IGT组(NIGT组);④FG异常的IGT组(AIGT组);⑤糖尿病组(DM组);根据1hG<9.16 mmol/L和1hG≥9.16 mmol/L分别将各组分为L1hG亚组和H1hG亚组.采用HOMA-IR、HOMA-β、Matsuda指数(ISIm)和AG/AI评估PCOS患者的糖代谢状况.结果 ①PCOS糖代谢异常的发生率为59.20％(531/897),其中DM占5.91％(53/897).②1hG、2hG和FG与ISIm的相关系数分别为-0.522、-0.490和-0.325,P=0.000.③IFG组的FG、1hG、HOMA-IR较NGT组显著升高、ISIm较NGT组显著降低,P=0.000;NIGT组的1hG、BMI、HOMA-IR、HOMA-β较NGT组显著增高、AG/AI、ISIm较NGT组显著降低,P=0.000.AIGT组的1hG、BMI、HOMA-IR、HOMA-β较IFG组显著增高,AG/AI、ISIm较IFG组显著降低,P=0.000.④NGT.H组,在HOMA-IR水平上,与IFG组和NIGT组差异无统计学意义(P>0.05);在ISIm水平上,与NIGT组和AIGT.L组差异无统计学意义(P>0.05);在AG/AI、HOMA-β水平上,与糖尿病前期各组差异无统计学意义,P均>0.05.结论 PCOS患者的1hG水平,在从NGT到DM前期直至DM的每个阶段,均显著性升高,并伴随有相应程度的糖代谢紊乱.在糖耐量正常的PCOS患者中,高1hG水平患者的糖代谢已经处于一定程度的紊乱状态.