Genome Mining and Gene Expression Reveal Maytansine Biosynthetic Genes from Endophytic Communities Living inside Gymnosporia heterophylla (Eckl. and Zeyh.) Loes. and the Relationship with the Plant Biosynthetic Gene, Friedelin Synthase

Abstract

Even though maytansine was first discovered from Celastraceae plants, it was later proven to be an endophytic bacterial metabolite. However, a pure bacterial culture cannot synthesize maytansine. Therefore, an exclusive interaction between plant and endophytes is required for maytansine production. Unfortunately, our understanding of plant–endophyte interaction is minimal, and critical questions remain. For example: how do endophytes synthesize maytansine inside their plant host, and what is the impact of maytansine production in plant secondary metabolites? Our study aimed to address these questions. We selected Gymnosporia heterophylla as our model and used amino-hydroxybenzoic acid (AHBA) synthase and halogenase genes as biomarkers, as these two genes respond to biosynthesize maytansine. As a result, we found a consortium of seven endophytes involved in maytansine production in G. heterophylla, based on genome mining and gene expression experiments. Subsequently, we evaluated the friedelin synthase (FRS) gene’s expression level in response to biosynthesized 20-hydroxymaytenin in the plant. We found that the FRS expression level was elevated and linked with the expression of the maytansine biosynthetic genes. Thus, we achieved our goals and provided new evidence on endophyte–endophyte and plant–endophyte interactions, focusing on maytansine production and its impact on plant metabolite biosynthesis in G. heterophylla.

Factors affecting the production of sugarcane yield and sucrose accumulation: suggested potential biological solutions

“…For instance, the application of an endophytic consortium improved crop production (Tripathi et al, 2020) and secondary metabolite production in different varieties of Catharanthus roseus (Singh et al, 2021b). The application of seven endophytic consortia enhanced maytansine biosynthesis, which is a potential antifungal agent (Pitakbut et al, 2022). Ganie et al (2022) recently examined the use of endophytes, especially their consortia, to obtain rice plants resilient to biotic and abiotic stress.…”

Sustainable Agriculture through the Enhancement of Microbial Biocontrol Agents: Current Challenges and New Perspectives

“…Howitz and Sinclair (2008) [42] hypothesized that homologous gene clusters present in plants and microorganisms may be cross activated by stress induced molecules, under certain conditions. A study by Pitakbut, Spiteller and Kayser (2022) [43] observed through gene analysis that endophytes associated with Gymnosporia heterophylla were responsible for the formation of maytansine through the expression of their AHBA synthase and halogenase genes. Alongside the expression of these genes and activation of the maytansine biosynthesis, the authors also observed an increase in the expression of the friedeline synthase genes in the plant.…”

Interaction of Plants and Endophytic Microorganisms: Molecular Aspects, Biological Functions, Community Composition, and Practical Applications

“…Moreover, two publications are concerned with the study of the effect of endophytes on plant secondary metabolism [ 9 , 10 ]. These studies described the influence of the grapevine bacterial and fungal endophytes on stilbene production in grape cells [ 9 ], the synthesis of cytotoxic macrolide maytansine by endophytes inside their plant host [ 10 ], and the impact of maytansine production on plant secondary metabolites [ 10 ].…”