Tian Yehan, Fu Xuesong, Zhang Gongchen, Zhang Rui, Kang Zhensheng, Gao Kexiang, Mendgen Kurt
Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Taian 271018, China.
Qingdao Academy of Agricultural Science, Qingdao 266100, China.
J Fungi (Basel). 2022 Feb 11;8(2):180. doi: 10.3390/jof8020180.
Endophytic fungi are effective in plant growth and development by secreting various kinds of plant hormones and nutrients. However, the cellular and molecular interactions between the endophytic fungi and plant growth-promoting have remained less explored. The present study was designed to explore the effects of the infection and colonization events of strain ND35 on cucumber growth and the expression pattern of some metabolically important genes in development of the cucumber radicle. The results demonstrated that strain ND35 can infect and colonize the outer layers (cortical cells) of cucumber root and form a symbiotic structure with the host cell, similar to a periarbuscular membrane and establish chemical communication with the plant. Through transcriptome analysis, we found the differentially expressed genes (DEGs) caused by strain ND35 were mainly enriched in phenylpropanoid biosynthesis, plant hormone signal transduction, plant-pathogen interaction and photosynthesis. Correspondingly, the contents of reactive oxygen species (ROS), hydrogen peroxide (HO), indole-3-acetic acid (IAA), gibberellin (GA), zeatin (ZT), salicylic acid (SA), jasmonic acid (JA) and the activity of phenylalanine ammonia lyase (PAL), 4-coumarate-CoA ligase (4CL), cinnamyl alcohol dehydrogenase (CAD), and peroxidase (POD) in ND35-colonized seedlings were generally higher than those of non-inoculated seedlings. Overall, the infection and colonization events of strain ND35 increased cucumber growth through complex regulation of plant hormones biosynthesis and metabolism. Furthermore, although the endophytic fungus strain ND35 produced IAA, GA, ZT, and ergosterol in the fermentation broth, and there are enabled to promote growth of cucumber, it is uncertain whether there are ND35-derived microbial hormones in plants. This study of the interaction between cucumber and strain ND35 contributes to a better understanding of the plant-endophytic fungi interactions, and may help to develop new strategies for crop production.
内生真菌通过分泌各种植物激素和营养物质对植物生长发育具有促进作用。然而，内生真菌与植物促生长之间的细胞和分子相互作用仍有待深入研究。本研究旨在探讨菌株ND35的侵染和定殖事件对黄瓜生长的影响以及黄瓜胚根发育过程中一些代谢重要基因的表达模式。结果表明，菌株ND35能够侵染并定殖于黄瓜根的外层（皮层细胞），并与宿主细胞形成类似于丛枝周膜的共生结构，且能与植物建立化学通讯。通过转录组分析，我们发现由菌株ND35引起的差异表达基因（DEGs）主要富集在苯丙烷生物合成、植物激素信号转导、植物-病原体相互作用和光合作用等方面。相应地，定殖有ND35的幼苗中活性氧（ROS）、过氧化氢（HO）、吲哚-3-乙酸（IAA）、赤霉素（GA）、玉米素（ZT）、水杨酸（SA）、茉莉酸（JA）的含量以及苯丙氨酸解氨酶（PAL）、4-香豆酸-CoA连接酶（4CL）、肉桂醇脱氢酶（CAD）和过氧化物酶（POD）的活性普遍高于未接种的幼苗。总体而言，菌株ND35的侵染和定殖事件通过对植物激素生物合成和代谢的复杂调控促进了黄瓜生长。此外，虽然内生真菌菌株ND35在发酵液中产生了IAA、GA、ZT和麦角固醇，且能够促进黄瓜生长，但尚不确定植物中是否存在源自ND35的微生物激素。本研究对黄瓜与菌株ND35之间相互作用的探讨有助于更好地理解植物-内生真菌相互作用，并可能有助于开发作物生产的新策略。
