Impact of heat and drought stress on peroxisome proliferation in quinoa.

Abstract

Although peroxisomes play a key role in plant metabolism under both normal and stressful growth conditions, the impact of drought and heat stress on the peroxisomes remains unknown. Quinoa represents an informative system for dissecting the impact of abiotic stress on peroxisome proliferation because it is adapted to marginal environments. Here we determined the correlation of peroxisome abundance with physiological responses and yield under heat, drought, and heat plus drought combination stresses in eight genotypes of quinoa. We found that all stresses caused a reduction in stomatal conductance and yield. Furthermore, H2O2 content increased under drought and heat plus drought. Principal component analysis demonstrated that peroxisome abundance correlated positively with H2O2 content in leaves and correlated negatively with yield. Person correlation coefficient for yield and peroxisome abundance (r=‐0.59) was higher than for commonly used photosynthetic efficiency (r=0.23), but comparable to those for classical stress indicators such as soil moisture content (r=0.51) or stomatal conductance (r=0.62). Our work established peroxisome abundance as a sensitive parameter for responses to heat and drought stress in the genetically diverse populations. As heat waves threaten agricultural productivity in arid climates, our findings will facilitate identification of genetic markers for improving yield of crops under extreme weather patterns.