Chen Yizhao, Ju Huimin, Li Hui, Xu Chang, Jia Hui, Xian Lijun, Yuan Chengjin, Guo Zexuan, Zhang Xijin, Yu Yilin, Tao Yongxin
College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Mycological Research Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Institute of Cash Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China.
J Photochem Photobiol B. 2024 Dec;261:113051. doi: 10.1016/j.jphotobiol.2024.113051. Epub 2024 Nov 2.
Flammulina filiformis, a representative umbelliferous fungus, has a long stipe and high l-lysine content, thus is widely cultivated and consumed. Currently, there is a lack of theoretical guidance on how to better use light to cultivate edible fungi without photosynthesis such as F. filiformis in industrialized cultivation. Previous studies have found that blue light can affect the yield and l-lysine content of F. filiformis. The primary focus of this work was the phytochrome PHY in the light signaling pathway and its role in F. filiformis production. Unlike plants in which the expression of PHY was activated by only red light, it was found that different visible lights (including red, blue, green, and white light) can stimulate the up-regulation of FfPhy transcript levels. Throughout the developmental stages of F. filiformis, the transcript level of FfPhy was significantly up-regulated during the formation of fruiting body and in the stipe in the elongation stage. Further, FfPhy knockdown strain showed the markedly shorter stipe length than WT, resulting in a significantly reduced yield. RNA-Seq analysis showed that the most genes in MAPK signaling pathway and its downstream regulatory processes, mainly focusing on cell division and cell wall remodeling, were down-regulated after FfPhy knockdown. It suggested that FfPhy regulates the fruiting body elongation through acting on cell division and cell wall remodeling, thereby affecting the morphological development of the stipe rather than the pileus. Interestingly, FfPhy knockdown also inhibits the accumulation of l-lysine content by promoting l-lysine degradation instead of inhibiting l-lysine biosynthesis, indicating that its influence extends to metabolic processes related to l-lysine metabolism. These findings provide new insights into photobiological effect of FfPhy in macrofungus F. filiformis, and have potential guiding significance for cultivation and breeding to increase mushroom yield and l-lysine content.
金针菇是一种典型的伞菌，菌柄长且L-赖氨酸含量高，因此被广泛种植和食用。目前，在工业化栽培中，对于如何更好地利用光照来培育像金针菇这样无光合作用的食用菌缺乏理论指导。先前的研究发现蓝光会影响金针菇的产量和L-赖氨酸含量。这项工作的主要重点是光信号通路中的光敏色素PHY及其在金针菇生产中的作用。与仅由红光激活PHY表达的植物不同，研究发现不同的可见光（包括红光、蓝光、绿光和白光）均可刺激金针菇FfPhy转录水平上调。在金针菇的整个发育阶段，FfPhy的转录水平在子实体形成期间以及菌柄伸长阶段均显著上调。此外，FfPhy基因敲除菌株的菌柄长度明显短于野生型，导致产量显著降低。RNA测序分析表明，丝裂原活化蛋白激酶（MAPK）信号通路及其下游调控过程中的大多数基因，主要集中在细胞分裂和细胞壁重塑方面，在FfPhy基因敲除后下调。这表明FfPhy通过作用于细胞分裂和细胞壁重塑来调节子实体伸长，从而影响菌柄而非菌盖的形态发育。有趣的是，FfPhy基因敲除还通过促进L-赖氨酸降解而非抑制L-赖氨酸生物合成来抑制L-赖氨酸含量的积累，表明其影响扩展到与L-赖氨酸代谢相关的代谢过程。这些发现为FfPhy在大型真菌金针菇中的光生物学效应提供了新的见解，对提高蘑菇产量和L-赖氨酸含量的栽培和育种具有潜在的指导意义。
