Cui Yanhong, Ji Xingzhou, Yu Wenjie, Liu Yang, Bai Qian, Su Shuchai
College of Forestry, Beijing Forestry University, Beijing 100083, China.
State Key Laboratory of Efficient Production of Forest Resources, Beijing 100083, China.
Int J Mol Sci. 2024 Apr 18;25(8):4454. doi: 10.3390/ijms25084454.
Ovule abortion significantly contributes to a reduction in chestnut yield. Therefore, an examination of the mechanisms underlying ovule abortion is crucial for increasing chestnut yield. In our previous study, we conducted a comprehensive multiomic analysis of fertile and abortive ovules and found that genes in chestnuts () play a crucial role in ovule development. Therefore, to further study the function of genes, a total of seven members were identified, their gene structures, conserved structural domains, evolutionary trees, chromosomal localization, and promoter cis-acting elements were analyzed, and their subcellular localization was predicted and verified. The spatiotemporal specificity of the expression of the seven genes was confirmed via qRT-PCR analysis. Notably, was exclusively expressed in the floral organs, and its expression peaked during fertilization and decreased after fertilization. The ACC levels remained consistently greater in fertile ovules than in abortive ovules. The ACSase activity of was identified using the genetic transformation of chestnut healing tissue. Micro plants overexpressing had a significantly greater rate of seed failure than did wild-type plants. Our results suggest that ovule fertilization activates and increases ACC levels, whereas an overexpression of leads to an increase in ACC content in the ovule prior to fertilization, which can lead to abortion. In conclusion, the present study demonstrated that chestnut ovule abortion is caused by poor fertilization and not by nutritional competition. Optimization of the pollination and fertilization of female flowers is essential for increasing chestnut yield and reducing ovule abortion.
胚珠败育显著导致板栗产量下降。因此，研究胚珠败育的潜在机制对于提高板栗产量至关重要。在我们之前的研究中，我们对可育和败育胚珠进行了全面的多组学分析，发现板栗中的基因在胚珠发育中起关键作用。因此，为了进一步研究基因的功能，共鉴定出7个成员，分析了它们的基因结构、保守结构域、进化树、染色体定位和启动子顺式作用元件，并对它们的亚细胞定位进行了预测和验证。通过qRT-PCR分析证实了这7个基因表达的时空特异性。值得注意的是，仅在花器官中表达，其表达在受精期间达到峰值，受精后下降。可育胚珠中的ACC水平始终高于败育胚珠。通过板栗愈伤组织的遗传转化鉴定了的ACSase活性。过表达的微型植株的种子败育率显著高于野生型植株。我们的结果表明，胚珠受精激活并增加ACC水平，而过表达会导致受精前胚珠中ACC含量增加，从而导致败育。总之，本研究表明板栗胚珠败育是由受精不良而非营养竞争引起的。优化雌花的授粉和受精对于提高板栗产量和减少胚珠败育至关重要。
