A Pseudomonas Plant Growth Promoting Rhizobacterium and Arbuscular Mycorrhiza differentially modulate the growth, photosynthetic performance, nutrients allocation, and stress response mechanisms triggered by a mild Zinc and Cadmium stress in tomato

Leilei Zhang; Monica Yorlady Alzate Zuluaga; Youry Pii; Angelica Barone; Stefano Amaducci; Begoña Miras-Moreno; Erika Martinelli; Gabriele Bellotti; Marco Trevisan; Edoardo Puglisi; Luigi Lucini

doi:10.1016/j.plantsci.2023.111873

A Pseudomonas Plant Growth Promoting Rhizobacterium and Arbuscular Mycorrhiza differentially modulate the growth, photosynthetic performance, nutrients allocation, and stress response mechanisms triggered by a mild Zinc and Cadmium stress in tomato

Plant Sci. 2023 Sep 20:337:111873. doi: 10.1016/j.plantsci.2023.111873. Online ahead of print.

Affiliations

¹ Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Piacenza, Italy.
² Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy.
³ Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy. Electronic address: youry.pii@unibz.it.
⁴ Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Piacenza, Italy.
⁵ Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Piacenza, Italy. Electronic address: edoardo.puglisi@unicatt.it.

PMID: 37739018
DOI: 10.1016/j.plantsci.2023.111873

Abstract

This study aimed to assess the effectiveness of plant growth-promoting rhizobacteria (PGPR; Pseudomonas strain So_08) and arbuscular mycorrhizal fungi (AMF; Rhizoglomus irregulare BEG72 and Funneliformis mosseae BEG234) in mitigating the detrimental effects of cadmium (Cd) and zinc (Zn) stress in tomato plants. Plant biomass, root morphology, leaf relative water content, membrane stability, photosynthetic performance, chlorophyll content, and heavy metals (HMs) accumulation were determined. Furthermore, an ionomic profile was conducted to investigate whether microbial inoculants affected the uptake and allocation of macro- and micronutrients. Metabolomics with pathway analysis of both roots and leaves was performed to unravel the mechanisms underlying the differential responses to HMs stress. The findings revealed that the levels of HMs did not significantly affect plant growth parameters; however, they affected membrane stability, photosynthetic performance, nutrient allocation, and chlorophyll content. Cadmium was mainly accumulated in roots, whilst Zn exhibited accumulation in various plant organs. Our findings demonstrate the beneficial effects of PGPR and AMF in mitigating Cd and Zn stress in tomato plants. The microbial inoculations improved physiological parameters and induced differential accumulation of macro- and micronutrients, modulating nutrient uptake balance. These results provide insights into the mechanisms underlying the plant-microbe interactions and highlight the differential modulation of the biosynthetic pathways of secondary metabolites related to oxidative stress response, membrane lipids stability, and phytohormone crosstalk.

Keywords: Abiotic stress; Heavy metals; Ionomics; Phytohormones; Rhizosphere; Stress tolerance mechanisms.