Overexpression of differentially expressed AhCytb6 gene during plant-microbe interaction improves tolerance to N2 deficit and salt stress in transgenic tobacco

Ankita Alexander,Vijay K Singh,Avinash Mishra

doi:10.1038/s41598-021-92424-4

Abstract

Stenotrophomonas maltophilia has plant growth-promoting potential, and interaction with Arachis hypogaea changes host-plant physiology, biochemistry, and metabolomics, which provides tolerance under the N2 starvation conditions. About 226 suppression subtractive hybridization clones were obtained from plant-microbe interaction, of which, about 62% of gene sequences were uncharacterized, whereas 23% of sequences were involved in photosynthesis. An uncharacterized SSH clone, SM409 (full-length sequence showed resemblance with Cytb6), showed about 4-fold upregulation during the interaction was transformed to tobacco for functional validation. Overexpression of the AhCytb6 gene enhanced the seed germination efficiency and plant growth under N2 deficit and salt stress conditions compared to wild-type and vector control plants. Results confirmed that transgenic lines maintained high photosynthesis and protected plants from reactive oxygen species buildup during stress conditions. Microarray-based whole-transcript expression of host plants showed that out of 272,410 genes, 8704 and 24,409 genes were significantly (p < 0.05) differentially expressed (> 2 up or down-regulated) under N2 starvation and salt stress conditions, respectively. The differentially expressed genes belonged to different regulatory pathways. Overall, results suggested that overexpression of AhCytb6 regulates the expression of various genes to enhance plant growth under N2 deficit and abiotic stress conditions by modulating plant physiology.

Highlights

Stenotrophomonas maltophilia has plant growth-promoting potential, and interaction with Arachis hypogaea changes host-plant physiology, biochemistry, and metabolomics, which provides tolerance under the N2 starvation conditions
Keeping this thought in mind, we have identified and clone genes that are differentially expressed in peanut in the response of interaction with Plant growth-promoting rhizobacteria (PGPR) (S. maltophilia) under the N2 starvation conditions (Fig. 1)
We reported the changes at the molecular level in the host plant after plant-microbe interaction

Summary

Introduction

Stenotrophomonas maltophilia has plant growth-promoting potential, and interaction with Arachis hypogaea changes host-plant physiology, biochemistry, and metabolomics, which provides tolerance under the N2 starvation conditions. Results suggested that overexpression of AhCytb[6] regulates the expression of various genes to enhance plant growth under N2 deficit and abiotic stress conditions by modulating plant physiology. The low availability of nitrogen in the soil decreases the yield of the crop, which could be compensated for by the application of N 2 fixing b acteria[11] In this scenario, we need diazotrophic bacteria that are tolerant to abiotic stress and act as PGPR to balance the nutrient cycle between the plant-microbe-soil dynamic in stress conditions. There is a need to understand the changes and events taking place at the molecular level in the host plant after interaction with PGPR under abiotic stress, and utilizing the differentially expressed gene for the potential candidate for the bioengineering of the host genome could be a highly translational strategy

Methods

Results

Discussion

Conclusion