State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, China.
Int J Mol Sci. 2024 Aug 27;25(17):9289. doi: 10.3390/ijms25179289.
Heat stress inhibits plant growth and productivity. Among the main regulators, B-box zinc-finger (BBX) proteins are well-known for their contribution to plant photomorphogenesis and responses to abiotic stress. Our research pinpoints that SlBBX31, a BBX protein harboring a conserved B-box domain, serves as a suppressor of plant growth and heat tolerance in tomato ( L.). Overexpressing (OE) in tomato exhibited yellowing leaves due to notable reduction in chlorophyll content and net photosynthetic rate (Pn). Furthermore, the pollen viability of OE lines obviously decreased and fruit bearing was delayed. This not only affected the fruit setting rate and the number of plump seeds but also influenced the size of the fruit. These results indicate that may be involved in the growth process of tomato, specifically in terms of photosynthesis, flowering, and the fruiting process. Conversely, under heat-stress treatment, knockout (KO) plants displayed superior heat tolerance, evidenced by their improved membrane stability, heightened antioxidant enzyme activities, and reduced accumulation of reactive oxygen species (ROS). Further transcriptome analysis between OE lines and KO lines under heat stress revealed the impact of on the expression of genes linked to photosynthesis, heat-stress signaling, ROS scavenging, and hormone regulation. These findings underscore the essential role of in regulating tomato growth and heat-stress resistance and will provide valuable insights for improving heat-tolerant tomato varieties.
热应激会抑制植物的生长和生产力。在主要的调节因子中，B 盒锌指（BBX）蛋白以其对植物光形态建成和非生物胁迫响应的贡献而闻名。我们的研究表明，SlBBX31 是一种含有保守 B 盒结构域的 BBX 蛋白，作为番茄生长和耐热性的抑制剂。在番茄中过表达 SlBBX31 会导致叶片变黄，因为叶绿素含量和净光合速率（Pn）明显降低。此外，OE 系的花粉活力明显下降，结实延迟。这不仅影响了果实的着果率和饱满种子的数量，还影响了果实的大小。这些结果表明 SlBBX31 可能参与了番茄的生长过程，特别是在光合作用、开花和果实形成过程中。相反，在热应激处理下，SlBBX31 敲除（KO）植株表现出更好的耐热性，其膜稳定性提高、抗氧化酶活性增强、活性氧（ROS）积累减少证明了这一点。在热应激下，OE 系和 KO 系之间的转录组分析进一步揭示了 SlBBX31 对与光合作用、热应激信号转导、ROS 清除和激素调节相关基因表达的影响。这些发现强调了 SlBBX31 在调节番茄生长和耐热性方面的重要作用，并将为改良耐热番茄品种提供有价值的信息。
