Plant growth promoting endophyte promotes cadmium accumulation in Solanum nigrum L. by regulating plant homeostasis

• Published in: Journal of hazardous materials 2023-09, Vol.457, p.131866-131866, Article 131866
• Main Authors: Chi, Yaowei, Ma, Xianzhong, Wu, Jianqiang, Wang, Renyuan, Zhang, Xia, Chu, Shaohua, Zhang, Dan, Zhou, Pei
• Format: Article
• Language: English
• Subjects: Amylase; Biodegradation, Environmental; Cadmium - metabolism; Endophytes - metabolism; Endosphere bacterial community; Homeostasis; Iron; Magnesium; PGPE; Plant Roots - metabolism; Soil - chemistry; Soil Pollutants - metabolism; Solanum nigrum - metabolism
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2023.131866

The homeostasis regulating mechanism of endophyte enhancing cadmium (Cd) extraction by hyperaccumulator is poorly understood. Here, an endophyte strain E3 that belonged to Pseudomonas was screened from Cd hyperaccumulator Solanum nigrum L., which significantly improved the Cd phytoextraction efficiency of S. nigrum by 40.26%. The content and translocation factor of nutrient elements indicated that endophyte might regulate Cd accumulation by affecting the uptake and transport of magnesium and iron in S. nigrum. Gene transcriptional expression profile further revealed that SnMGT, SnIRT1, and SnIRT2, etc., were the key genes involved in the regulation of S. nigrum elements uptake by endophyte. However, changes in elemental homeostasis did not negatively affect plant growth. Endophyte inoculation promoted plant growth by fortifying photosynthesis as well as recruiting specific bacteria in S. nigrum endosphere, e.g., Pseudonocardiaceae, Halomonas. Notably, PICRUSt2 analysis and biochemical characterization jointly suggested that endophyte regulated starch degradation in S. nigrum leaves to maintain photosynthetic balance. Our results demonstrated that microecological characteristics of hyperaccumulator could be reshaped by endophyte, also the homeostasis regulation in endophyte enhanced hyperaccumulator Cd phytoextraction was significant. [Display omitted] •Endophyte Pseudomonas sp. E3 significantly increased S. nigrum Cd accumulation.•Strain E3 enhanced S. nigrum leaf amylase activity to maintain photosynthesis system balance.•Strain E3 affected Cd enrichment by S. nigrum through regulation of Fe and Mg uptake and transport.•Strain E3 had limited effect on S. nigrum endosphere bacterial community diversity and structure.•Strain E3 recruit specific bacteria in S. nigrum, e.g., Pseudonocardiaceae, Halomonas.