Community structure and diversity of endophytic bacteria in seeds of three consecutive generations of Crotalaria pumila growing on metal mine residues

• Published in: Plant and soil Vol. 422; no. 1/2; pp. 51 - 66
• Main Authors: Sánchez-López, Ariadna S., Thijs, Sofie, Beckers, Bram, González-Chávez, Ma. Carmen, Weyens, Nele, Carrillo-González, Rogelio, Vangronsveld, Jaco
• Format: Journal Article
• Language: English
• Published: Cham Springer 01-01-2018; Springer International Publishing; Springer Nature B.V
• Subjects: Angiosperms; Arid regions; Arid zones; Bacteria; Biomedical and Life Sciences; Communities; Community structure; Contamination; Crotalaria pumila; Deoxyribonucleic acid; DNA; Ecology; Endophytes; Life Sciences; Microbiomes; Mine soils; Oxidative phosphorylation; Phosphorylation; Photosynthesis; Physiological aspects; Phytoremediation; Plant growth; Plant Physiology; Plant Sciences; Plant-soil relationships; Regular Article; Residues; rRNA 16S; Seeds; Semiarid lands; Soil Science & Conservation; Mexico; Bacterial seed endophytes; Trace metals; Pyrosequencing; Phytoremediation
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-017-3176-2

Aims We investigated the possible transgenerational transfer of bacterial seed endophytes across three consecutive seed generations of Crotalaria pumila growing on a metal mining site in Mexico. Methods Seeds were collected during three successive years in the semi-arid region of Zimapan, Mexico. Total communities of seed endophytes were investigated using DNA extraction from surface sterilized seeds and 454 pyrosequencing of the V5-V7 hypervariable regions of the 16S rRNA gene. Results The communities consisted of an average of 75 operational taxonomic units (OTUs); richness and diversity did not change across years. Methylobacterium, Staphylococcus, Corynebacterium, Propionibacterium and eight other OTUs constituted >60% of the community in each generation The microbiome was dominated by Methylobacterium (present in >80% of samples). Functions associated with the microbiome were C and N fixation, oxidative phosphorylation and photosynthesis activity. Conclusions The bacterial endophytic communities were similar across three consecutive seed generations. Among the core microbiome Methylobacterium strains were the most abundant and they can contribute to nutrient acquisition, plant growth promotion and stress resilience to their host in metal contaminated mine residues. Identification of the seed microbiome of C. pumila may lead to novel and more efficient inoculants for microbe-assisted phytoremediation.