Mechanisms in Growth-Promoting of Cucumber by the Endophytic Fungus Chaetomium globosum Strain ND35

Abstract

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 Chaetomium globosum 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 (H2O2), 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 C. globosum 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.

Nuclear Genome Sequence and Gene Expression of an Intracellular Fungal Endophyte Stimulating the Growth of Cranberry Plants

“…In most studies examining the nature of symbiont genes, the expression of which is altered by the plant host, microbes are cultivated in the presence of plant extract prior to sequencing their transcriptome [ 81 , 82 , 83 ]. To simulate the microbe-plant interaction more realistically, we cultivated EC4 in the presence (and absence) of the roots from a live cranberry seedling (for the experimental set-up, see Figure 1 ).…”

Comparative metataxonamic analyses of seeds and leaves of traditional varieties and hybrids of cucumber (Cucumis sativus L.) reveals distinct and core microbiome

“…Some of the endophytic microbes reported in cucumber are: Chryseobacterium [ 20 ], Chaetomium [ 21 ], Paenibacillus [ 22 ], Paecilomyces [ 23 ], Saccharothrix [ 24 ], Aspergillus, Penicillium, Fusarium, Beauveria, Trichoderma, Colletotrichum, Cladosporium, Alternatia, Chaetomium [ 25 ], Fusarium, Chaetomium, Colletotrichum, Acrocalymma [ 26 ]. The Pencillium, Gignardia, Hypocrea, Neurospora, Eupenicillium, Lasiodiplodia observed by Abro et al [ 27 ] were found to have antagonistic activity against Fusarium oxysporum f.sp.…”

Taxonomy and Phylogeny of Endophytic Fungi (Chaetomiaceae) Associated with Healthy Leaves of Mangifera indica in Yunnan, China

“…Chaetomiaceae synthesizes many secondary metabolites with different chemical structures and shows outstanding bioactivities [57]. Species of the Chaetomiaceae are used as biological control agents for various plant diseases, as well as as bio-organic fertilizers in crop cultivation [9,15,58]. On top of that, Chaetomium species are reported as versatile weapons against various plant pathogens and act as growth promoters in maize (Zea mays), cucumbers (Cucumis sativus), and Agaricus bisporus (edible mushroom) [9,[59][60][61].…”

“…Species of the Chaetomiaceae are used as biological control agents for various plant diseases, as well as as bio-organic fertilizers in crop cultivation [9,15,58]. On top of that, Chaetomium species are reported as versatile weapons against various plant pathogens and act as growth promoters in maize (Zea mays), cucumbers (Cucumis sativus), and Agaricus bisporus (edible mushroom) [9,[59][60][61]. Most importantly, the species in Chaetomiaceae produce industrially relevant enzymes, significantly benefiting agriculture, biotechnology, ecosystems, food production, and human health [15,62].…”

“…Fungal endophytes are an intriguing group that resides within the intracellular and/or extracellular spaces of plant tissues without causing any adverse effects or visible disease symptoms among the hosts [5]. Endophytic fungi offer a number of benefits to plants, such as protecting hosts from abiotic (e.g., drought, high temperature, and waterlogging) and biotic (e.g., pathogens and insect pests) stresses and promoting plant growth and germination [6][7][8][9]. Moreover, owing to their numerous properties, such as anticancer, antidiabetic, biocontrol, immunosuppressive, and insecticidal potentials, endophytes are often used in agricultural, industrial, pharmaceutical, and medical sectors [10][11][12].…”