Seed Endophyte Microbiome of Crotalaria pumila Unpeeled: Identification of Plant-Beneficial Methylobacteria

• Published in: International journal of molecular sciences Vol. 19; no. 1; p. 291
• Main Authors: Sánchez-López, Ariadna S, Pintelon, Isabel, Stevens, Vincent, Imperato, Valeria, Timmermans, Jean-Pierre, González-Chávez, Carmen, Carrillo-González, Rogelio, Van Hamme, Jonathan, Vangronsveld, Jaco, Thijs, Sofie
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 19-01-2018; MDPI
• Subjects: Confocal microscopy; Crotalaria - growth & development; Crotalaria - metabolism; Crotalaria - microbiology; Crotalaria pumila; Endophytes; Endophytes - growth & development; Endophytes - metabolism; Environmental Pollution; Flowering; Germination; metalliferous soil; Metals - metabolism; Metals - toxicity; Methylobacterium; Methylobacterium - metabolism; Microbiomes; Microbiota; Microbiota - genetics; Microorganisms; Plant Development; plant growth-promoting endophyte; Plant Roots - chemistry; seed core microbiome; Seed germination; Seedlings; Seeds; Seeds - metabolism; Seeds - microbiology; Soil contamination; Soil Microbiology; Soil Pollutants - metabolism; Soil Pollutants - toxicity; Symbiosis; trace metals; Xylem; xylem; plant growth-promoting endophyte; seed core microbiome; trace metals; Methylobacterium; metalliferous soil
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms19010291

Metal contaminated soils are increasing worldwide. Metal-tolerant plants growing on metalliferous soils are fascinating genetic and microbial resources. Seeds can vertically transmit endophytic microorganisms that can assist next generations to cope with environmental stresses, through yet poorly understood mechanisms. The aims of this study were to identify the core seed endophyte microbiome of the pioneer metallophyte
throughout three generations, and to better understand the plant colonisation of the seed endophyte
sp. Cp3. Strain Cp3 was detected in
seeds across three successive generations and showed the most dominant community member. When inoculated in the soil at the time of flowering, strain Cp3 migrated from soil to seeds. Using confocal microscopy, Cp3-mCherry was demonstrated to colonise the root cortex cells and xylem vessels of the stem under metal stress. Moreover, strain Cp3 showed genetic and
potential to promote seed germination and seedling development. We revealed, for the first time, that the seed microbiome of a pioneer plant growing in its natural environment, and the colonisation behaviour of an important plant growth promoting systemic seed endophyte. Future characterization of seed microbiota will lead to a better understanding of their functional contribution and the potential use for seed-fortification applications.