Cross‐inoculation of rhizobiome from a congeneric ruderal plant imparts drought tolerance in maize (Zea mays) through changes in root morphology and proteome. (8th June 2022)

• Record Type: Journal Article
• Authors: Zhang, Ziliang; Jatana, Bhupinder Singh; Campbell, Barbara J.; Gill, Jasmine; Suseela, Vidya; Tharayil, Nishanth
• Is Part Of: Plant journal. Volume 111:Number 1(2022)
• Page Start: 54
• Page End: 71
• Publication Date: 2022-06-08
• Subjects: Andropogon virginicus -- cross‐inoculation -- drought stress -- drought resilience -- maize -- rhizobiome -- root -- phytohormones; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.15775
• Languages: English
• ISSNs: 0960-7412

Abstract

SUMMARY: Rhizobiome confer stress tolerance to ruderal plants, yet their ability to alleviate stress in crops is widely debated, and the associated mechanisms are poorly understood. We monitored the drought tolerance of maize ( Zea mays ) as influenced by the cross‐inoculation of rhizobiota from a congeneric ruderal grass Andropogon virginicus ( andropogon‐inoculum ), and rhizobiota from organic farm maintained under mesic condition ( organic‐inoculum ). Across drought treatments (40% field capacity), maize that received andropogon‐inoculum produced two‐fold greater biomass. This drought tolerance translated to a similar leaf metabolomic composition as that of the well‐watered control (80% field capacity) and reduced oxidative damage, despite a lower activity of antioxidant enzymes. At a morphological‐level, drought tolerance was associated with an increase in specific root length and surface area facilitated by the homeostasis of phytohormones promoting root branching. At a proteome‐level, the drought tolerance was associated with upregulation of proteins related to glutathione metabolism and endoplasmic reticulum‐associated degradation process. Fungal taxa belonging to Ascomycota, Mortierellomycota, Archaeorhizomycetes, Dothideomycetes, and Agaricomycetes in andropogon‐inoculum were identified as potential indicators of drought tolerance. Our study provides a mechanistic understanding of the rhizobiome‐facilitated drought tolerance and demonstrates a better path to utilize plant–rhizobiome associations to enhance drought tolerance in crops. Significance Statement: The rhizobiome from a drought‐tolerant ruderal plant ( Andropogon virginicus ) alleviates drought‐induced physiological stress of maize ( Zea mays ) through modifications in root morphology driven by homeostasis of phytohormones and stress‐related proteome upregulations. Thus our study captures the underlying mechanisms through which rhizobiome facilitates drought tolerance in maize, and highlight the importance of cross‐inoculation of rhizobiota from stress‐resilient cogeneric species.