Plants face constant threats from pathogens, leading to growth retardation and crop failure. Cell-surface leucine-rich repeat receptor-like kinases (LRR-RLKs) are crucial for plant growth and defense, but their specific functions, especially to necrotrophic fungal pathogens, are largely unknown. Here, we identified an LRR-RLK (Solyc06g069650) in tomato (Solanum lycopersicum) induced by the economically important necrotrophic pathogen Botrytis cinerea. Knocking out this LRR-RLK reduced plant growth and increased sensitivity to B. cinerea, while its overexpression led to enhanced growth, yield, and resistance. We named this LRR-RLK as BRAK (B. cinerea resistance-associated kinase). Yeast two-hybrid screen revealed BRAK interacted with phytosulfokine (PSK) receptor PSKR1. PSK-induced growth and defense responses were impaired in pskr1, brak single and double mutants, as well as in PSKR1-overexpressing plants with silenced BRAK. Moreover, BRAK and PSKR1 phosphorylated each other, promoting their interaction as detected by microscale thermophoresis. This reciprocal phosphorylation was crucial for growth and resistance. In summary, we identified BRAK as a novel regulator of seedling growth, fruit yield and defense, offering new possibilities for developing fungal disease-tolerant plants without compromising yield.

中文翻译：

---

一种新的 LRR 受体样激酶 BRAK 相互磷酸化 PSKR1 以增强番茄的生长和防御。


植物不断面临病原体的威胁，导致生长迟缓和作物歉收。细胞表面富含亮氨酸的重复受体样激酶 （LRR-RLK） 对植物生长和防御至关重要，但它们的特定功能，尤其是对坏死性真菌病原体的功能，在很大程度上是未知的。在这里，我们在具有重要经济意义的坏死营养病原体灰霉菌诱导的番茄 （Solanum lycopersicum） 中鉴定了一个 LRR-RLK （Solyc06g069650）。敲除这种 LRR-RLK 会减少植物生长并增加对灰葡萄孢杆菌的敏感性，而其过表达会导致生长、产量和抗性增强。我们将这个 LRR-RLK 命名为 BRAK （B. cinerea 抗性相关激酶）。酵母双杂交筛选显示 BRAK 与植物砜碱 （PSK） 受体 PSKR1 相互作用。PSK 诱导的生长和防御反应在 pskr1、brak 单和双突变体以及具有沉默 BRAK 的 PSKR1 过表达植物中受损。此外，BRAK 和 PSKR1 相互磷酸化，促进它们相互作用，通过微量热泳检测到。这种相互磷酸化对于生长和抗性至关重要。总之，我们确定 BRAK 是幼苗生长、果实产量和防御的新型调节因子，为在不影响产量的情况下开发耐真菌植物提供了新的可能性。