背景回顾：Male sterility enables hybrid crop breeding to increase yields and has been extensively studied. But thermo-sensitive female sterility, which is an ideal property that may enable full mechanization in hybrid rice breeding, has rarely been investigated due to the absence of such germplasm. 

主要发现：Here we identify the spontaneous thermo-sensitive female sterility 1 (tfs1) mutation that confers complete sterility under regular/high temperature and partial fertility under low temperature as a point mutation in ARGONAUTE7 (AGO7). 

结果1-AGO7-miR390-TAS3-tasi-ARFs：AGO7 associates with miR390 to form an RNA-Induced Silencing Complex (RISC), which triggers the biogenesis of small interfering RNAs (siRNAs) from TRAN-ACTING3 (TAS3) loci by recruiting SUPPRESSOR OF GENE SILENCING (SGS3) and RNA-DEPENDENT RNA POLYMERASE6 (RDR6) to TAS3 transcripts. These siRNAs are known as tasiR-ARFs as they act in trans to repress auxin response factor genes.

结果2-AGO7-miR390模块：The mutant TFS1 (mTFS1) protein is compromised in its ability to load the miR390/miR390* duplex and eject miR390* during RISC formation. Furthermore, tasiR-ARF levels are reduced in tfs1 due to the deficiency in RDR6 but not SGS3 recruitment by mTFS1 RISC under regular/high temperature, while low temperature partially restores mTFS1 function in RDR6 recruitment and tasiR-ARF biogenesis. A miR390 mutant also exhibits female sterility, suggesting that female fertility is controlled by the miR390-AGO7 module.

结果3-实践应用：Notably, the tfs1 allele introduced into various elite rice cultivars endows thermo-sensitive female sterility. Moreover, field trials confirm the utility of tfs1 as a restorer line in fully mechanized hybrid rice breeding.

 摘 要 

雄性不育帮助作物杂交育种提高产量，已被广泛研究。但由于缺乏温敏性的雌性不育种质，关于该方向的研究一直停滞不前，从而阻碍了农作物杂交育种的进一步优化和改良。本文中，作者鉴定到了一个自然产生的温敏性雌性不育突变体tfs1，发现该突变体的突变基因为AGO7，该基因的一个点突变导致了tfs1突变体在正常和高温条件下表现出完全不育，而在低温条件下表现出部分不育。AGO7与miR390的结合，形成一个RNA诱导的沉默复合物（RISC），该复合物通过招募基因沉默抑制因子SGS3和RNA依赖性RNA聚合酶RDR6到TAS3的转录本上，介导TAS3基因位点上小的干扰RNA（siRNA）的生物发生。这些siRNA被称为tasiR-ARF，其以反式作用抑制生长素响应因子基因。突变后的TFS1蛋白mTFS1降低了RISC过程中，装载miR390/miR390*双链体和排出miR390*的能力。此外，在正常或者高温条件下，tfs1突变体中tasiR-ARF水平下降是由于mTFS1 RISC招募RDR6蛋白、而非SGS3蛋白的缺乏所导致的，而低温部分恢复了mTFS1对于RDR6蛋白的招募功能以及tasiR-ARF生物发生。一个miR390突变体会表现出了雌性不育，表明雌性育性是由miR390-AGO7模块来控制的。值得注意的是，将tfs1等位基因引入各种优异的水稻品种，均成功建立起了温敏性雌性不育。此外，大田试验进一步证实了tfs1作为恢复系，在全机械化杂交水稻育种中的实践应用能力。