Abstract

Globally, many low to medium yielding peanut fields have the potential for further yield improvement. Low phosphorus (P) limitation is one of the significant factors curtailing Arachis hypogaea productivity in many regions. In order to demonstrate the effects of gamma-aminobutyric acid (GABA) on peanuts growing under P deficiency, we used a pot-based experiment to examine the effects of exogenous GABA on alleviating P deficiency-induced physiological changes and growth inhibition in peanuts. The key physiological parameters examined were foliar gas exchange, photochemical efficiency, proton motive force, reactive oxygen species (ROS), and adenosine triphosphate (ATP) synthase activity of peanuts under cultivation with low P (LP, 0.5 mM P) and control conditions. During low P, the cyclic electron flow (CEF) maintained the high proton gradient (∆pH) induced by low ATP synthetic activity. Applying GABA during low P conditions stimulated CEF and reduced the concomitant ROS generation and thereby protecting the foliar photosystem II (PSII) from photoinhibition. Specifically, GABA enhanced the rate of electronic transmission of PSII (ETRII) by pausing the photoprotection mechanisms including non-photochemical quenching (NPQ) and ∆pH regulation. Thus, GABA was shown to be effective in restoring peanut growth when encountering P deficiency. Exogenous GABA alleviated two symptoms (increased root-shoot ratio and photoinhibition) of P-deficient peanuts. This is possibly the first report of using exogenous GABA to restore photosynthesis and growth under low P availability. Therefore, foliar applications of GABA could be a simple, safe and effective approach to overcome low yield imposed by limited P resources (low P in soils or P-fertilizers are unavailable) for sustainable peanut cultivation and especially in low to medium yielding fields.

Keywords

Exogenous and non-toxic GABA; Peanut; P deficiency; Thylakoid lumen acidification; Photoprotection

Published in

Ecotoxicology and Environmental Safety
2023, Volume: 263, article number: 115388

SLU Authors

• Yong, Jean W.H

  • Department of Biosystems and Technology, Swedish University of Agricultural Sciences
    
  • University of Western Australia

Sustainable Development Goals

Ensure availability and sustainable management of water and sanitation for all
End hunger, achieve food security and improved nutrition and promote sustainable agriculture
Ensure sustainable consumption and production patterns


UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.1016/j.ecoenv.2023.115388

Permanent link to this page (URI)

https://res.slu.se/id/publ/119062