A cellular mechanism underlying the restoration of thermo/photoperiod-sensitive genic male sterility
A cellular mechanism underlying the restoration of thermo/photoperiod-sensitive genic male sterility
复制标题
热/光敏感基因雄性不育恢复的细胞机制
DOI：
10.1016/j.molp.2021.08.019
复制
发表时间：
2021-12-06
期刊：
影响因子：
27.5
通讯作者：
Yang, Zhong-Nan
中科院分区：
文献类型：
--
作者：
Shi, Qiang-Sheng;Lou, Yue;Yang, Zhong-Nan
在花药发育过程中，小孢子向成熟花粉的转化是在四分体壁和花粉壁的保护下进行的。参与这种壁转变的基因突变通常导致小孢子破裂和雄性不育;一些这样的突变体，如可逆雄性不育（rvms）突变体，是温/光敏感核雄性不育（P/TGMS）系。以往的研究表明，发育缓慢伊萨P/TGMS育性恢复的一般机制。在这项研究中，我们鉴定了rvms-2（res 2）的恢复，它是QUARTET 3（QRT 3）的一个等位基因，编码一种多聚半乳糖醛酸酶，显示四分体果胶壁的延迟降解。我们发现，绒毡层特异性转录因子MS 188能够激活QRT 3的表达，从而促进果胶的降解，这表明细胞壁转变的调控可能是一条非细胞自主的途径。进一步的研究表明，四分体果胶壁降解的延迟是rvms和其他P/TGMS系育性恢复的原因，而QRT 3的早期表达消除了rvms-2育性的低温恢复。综上所述，这些结果表明，在P/TGMS系育性恢复的细胞机制，即，缓慢的发展过程中的细胞壁转换的P/TGMS小孢子可能会减少其壁保护的要求，从而支持其发展成功能花粉，导致恢复的育性。
During anther development, the transformation of the microspore into mature pollen occurs under the pro-tection of first the tetrad wall and later the pollen wall. Mutations in genes involved in this wall transition often lead to microspore rupture and male sterility; some such mutants, such as the reversible male sterile (rvms) mutant, are thermo/photoperiod-sensitive genic male sterile (P/TGMS) lines. Previous studies have shown that slow development isa general mechanism of P/TGMS fertility restoration. In this study, we iden-tified restorer of rvms-2 (res2), which is an allele of QUARTET 3 (QRT3) encoding a polygalacturonase that shows delayed degradation of the tetrad pectin wall. We found that MS188, a tapetum-specific transcrip-tion factor essential for pollen wall formation, can activate QRT3 expression for pectin wall degradation, indicating a non-cell-autonomous pathway involved in the regulation of the cell wall transition. Further as-says showed that a delay in degradation of the tetrad pectin wall is responsible for the fertility restoration of rvms and other P/TGMS lines, whereas early expression of QRT3 eliminates low temperature restoration of rvms-2 fertility. Taken together, these results suggest a likely cellular mechanism of fertility restoration in P/TGMS lines, that is, slow development during the cell wall transition of P/TGMS microspores may reduce the requirement for their wall protection and thus support their development into functional pollens, leading to restored fertility.