Aspergillus Niger 129B induces the SAUR32-PP2C72 interaction to promote plant growth

Juan He¹Yuan Li Gao¹Ping Yong Luo¹Min Chai¹Feng Hua Wang¹Hong Lu Yang¹Kang Zhao¹Yujiangshan Maimaiti²Jun Yuan Nie^3*Wei Chen^1*

• ¹School of Life Science, Shanxi Normal University, Shanxi, China
• ²xinjiang Institute of Plant Protection, Urumqi, China
• ³Shanxi Agricultural University, Taiyuan, China

Plant growth-promoting fungi (PGPF) are fundamental to plant growth such as nutrient acquisition and root growth. However, the growth promotion mechanisms regulated by Aspergillus Niger is poorly characterized. In this study, we examined the growth-promoting effects of the Aspergillus Niger 129B on tomato plant of root, stem, and leaf development through a combination of phenotype analyses and plant biomass measurement; subsequently, the molecular and genetic experiments were conducted to reveal the mechanism in promoting root, stem, and leaf development. The results demonstrated that 129B significantly promoted the growth of tomato plant. Plant transcriptome and metabolome analysis proved that this effect was associated with plant hormone signaling pathway of SAUR32 and PP2C72 gene expression. In addition, 129B could promote the tissues of root, stem, and leaf development by down-regulating the SAUR32 and PP2C72 gene expression. Importantly, we found that the promotion of tissues development may be attributed to the interaction between SAUR32 and PP2C72, the expression of SAUR32 proteins that act as inhibitors of PP2C72 phosphatases triggered the root H + efflux. Our findings concluded that 129B-induced plant promotion is dependent on the interaction between SAUR32 and PP2C72, supporting novel insights into plant-microbiome beneficial interactions.