MATERNAL AUTOPHAGY CONTRIBUTES TO GRAIN YIELD IN MAIZE

Abstract

Maize is an important crop species that is cultivated worldwide, and increasing maize yield is one of the major goals of plant breeding. The subcellular degradation and recycling pathway known as autophagy is involved in many plant developmental processes including vegetative growth, reproductive development, seed development, and senescence. Here, we demonstrate that maize autophagy-defective atg10 mutants have delayed flowering and reduced kernel size, weight and number, leading to reduced grain yield. Reciprocal crosses between mutant and parental lines indicate that the maternal plant is the major contributor to the kernel phenotype in atg10 mutants, rather than the seed genotype. We hypothesize that this may be due to detrimental effects on nutrient remobilization from maternal tissue to seeds during kernel development, leading to reduced yield.