The degree of stigma exsertion has a major influence on self-pollination efficiency in tomato, and its improvement is essential for raising productivity and for fixing advantageous traits in cultivated tomato. To study the evolution of stigma exsertion degree in tomato, we searched for genes associated with this trait and other aspects of flower morphology, including the lengths of anthers, styles, and ovaries. We performed a genome-wide association on 277 tomato accessions and discovered a novel stigma exsertion gene (SE3.1). We reannotated the structure of the gene, which encodes a C2H2-type zinc finger transcription factor. A mutation of the lead single nucleotide polymorphism creates a premature termination codon in SE3.1 and an inserted stigma in cultivated tomatoes. SE3.1 is essential for the conversion of flush stigmas to inserted stigmas. This conversion has a major impact on the rate of self-fertilization. Intriguingly, we found that both SE3.1 and Style2.1 contribute to the transition from stigma exsertion to insertion during the domestication and improvement of tomato. Style2.1 controls the first step of exserted stigmas to flush stigmas, and SE3.1 controls the second step of flush stigmas to inserted stigmas. We provide molecular details for the two-step process that controls the transition from stigma exsertion to insertion, which is of great agronomic importance in tomato.

中文翻译：

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C2H2型锌指转录因子的突变有助于栽培番茄向自花授粉的转变

柱头外露程度对番茄的自花授粉效率有重要影响，其改进对于提高栽培番茄的生产力和固定优势性状至关重要。为了研究番茄柱头外露程度的演变，我们搜索了与该性状和花形态的其他方面相关的基因，包括花药的长度、花柱和子房。我们对 277 个番茄种质进行了全基因组关联，发现了一个新的柱头外露基因 (SE3.1)。我们重新注释了编码 C2H2 型锌指转录因子的基因结构。前导单核苷酸多态性的突变在 SE3.1 中产生了一个提前终止密码子，并在栽培番茄中产生了一个插入的柱头。SE3.1 对于将同花柱头转化为插入柱头至关重要。这种转换对自我受精率有重大影响。有趣的是，我们发现在番茄驯化和改良过程中，SE3.1 和 Style2.1 都有助于从柱头外露到插入的转变。Style2.1控制柱头外露第一步齐平柱头，SE3.1控制柱头齐平到插入柱头第二步。我们为控制从柱头外露到插入的转变的两步过程提供了分子细节，这在番茄中具有重要的农艺学意义。SE3.1 控制第二步将柱头冲洗到插入柱头。我们为控制从柱头外露到插入的转变的两步过程提供了分子细节，这在番茄中具有重要的农艺学意义。SE3.1 控制第二步将柱头冲洗到插入柱头。我们为控制从柱头外露到插入的转变的两步过程提供了分子细节，这在番茄中具有重要的农艺学意义。