近日，植物细胞《The Plant Cell》在线发表了武汉大学生命科学学院朱英国院士等研究人员的最新成果。这篇题为“The Rice Pentatricopeptide Repeat Protein RF5 Restores Fertility in Hong-Lian Cytoplasmic Male-Sterile Lines via a Complex with the Glycine-Rich Protein GRP162”的文章，阐明了红莲型杂交稻的育性恢复机理，并首次提出恢复基因分子复合体。

杂交水稻是由不育系做母本，恢复系做父本得到的杂交种子，这些杂交种子拥有着比父母本更强的优势，如产量、米质等，然而，恢复系是如何使不育系的育性得到恢复这一问题却困扰了科学家和育种家数十年。

在这篇文章中，研究人员通过大量实验证明，红莲型水稻恢复基因RF5不能直接结合不育基因RNA，而是组装成恢复基因分子复合体（Restoration of Fertility Complex，RFC）去结合并剪切不育基因RNA，从而完成了育性恢复的使命，并发现了复合体中与恢复基因互作的重要亚基成分GRP162。该项研究从DNA、RNA、Protein不同层面上报道了这一育性恢复的生物学机制。

论文摘要：

The cytoplasmic male sterility (CMS) phenotype in plants can be reversed by the action of nuclear-encoded fertility restorer (Rf) genes. The molecular mechanism involved in Rf gene–mediated processing of CMS-associated transcripts is unclear, as are the identities of other proteins that may be involved in the CMS–Rf interaction. In this study, we cloned the restorer gene Rf5 for Hong-Lian CMS in rice and studied its fertility restoration mechanism with respect to the processing of the CMS-associated transcript atp6-orfH79. RF5, a pentatricopeptide repeat (PPR) protein, was unable to bind to this CMS-associated transcript; however, a partner protein of RF5 (GRP162, a Gly-rich protein encoding 162 amino acids) was identified to bind to atp6-orfH79. GRP162 was found to physically interact with RF5 and to bind to atp6-orfH79 via an RNA recognition motif. Furthermore, we found that RF5 and GRP162 are both components of a restoration of fertility complex (RFC) that is 400 to 500 kD in size and can cleave CMS-associated transcripts in vitro. Evidence that a PPR protein interacts directly with a Gly-rich protein to form a subunit of the RFC provides a new perspective on the molecular mechanisms underlying fertility restoration.

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