Genetius

A comprehensive multi‑environment trial of 437 maize testcross hybrids derived from 38 MLN‑tolerant lines and 29 testers identified additive genetic effects as the primary driver of grain yield, disease resistance, and drought tolerance. Strong general combining ability and specific combining ability patterns were uncovered, with top hybrids delivering up to 5.75 t ha⁻¹ under MLN pressure while maintaining high performance under optimum and drought conditions. The study provides a framework for selecting elite parents and exploiting both additive and non‑additive effects to develop resilient maize hybrids for sub‑Saharan Africa.

Double mutant hybrids in the miR394‑regulated genes ZmLCR1 and ZmLCR2, created in a W22/B73 maize background, display enhanced drought tolerance through increased epicuticular wax and reduced ROS production, while maintaining normal flowering and nutrition. Under field rainfed conditions the mutants achieve significantly higher yields (greater ear weight and kernel number) compared to wild‑type hybrids.

The study identifies fungal effectors from Ustilago maydis that interact with plant TOPLESS corepressors and induce gall formation by hijacking maize lateral root initiation pathways, notably through upregulation of LBD transcription factors. Transgenic expression of class II effectors derepresses auxin signaling, leading to pluripotent calli without external hormones, and maize mutants in LBD genes show reduced gall development.

The study tracked molecular changes in plastoglobules and thylakoids of Zea mays B73 during heat stress and recovery, revealing increased plastoglobule size, number, and adjacent lipid droplets over time. Proteomic and lipidomic analyses uncovered up‑regulation of specific plastoglobule proteins and alterations in triacylglycerol, plastoquinone derivatives, and phytol esters, suggesting roles in membrane remodeling and oxidative defense. These insights highlight plastoglobule‑associated pathways as potential targets for enhancing heat resilience in maize.