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.

The study provides a comprehensive genome-wide catalog and single‑cell expression atlas of the carbonic anhydrase (CA) gene family in maize, identifying 18 CA genes across α, β, and γ subfamilies and detailing their structural and regulatory features. Phylogenetic, synteny, promoter motif, bulk tissue RNA‑seq, and single‑cell RNA‑seq analyses reveal distinct tissue and cell‑type specific expression patterns, highlighting β‑CAs as key players in C4 photosynthesis and γ‑CAs in ion/pH buffering, and propose cell‑type‑specific CA genes as targets for improving stress resilience.

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 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.

The study analyzes ancient maize genomes from a 500–600 BP Bolivian offering and compares them with 16 archaeological samples spanning 5,000 years and 226 modern Zea mays lines, revealing close genetic affinity to ancient Peruvian maize and increased diversity during Inca‑local interactions. Phylogenetic and phenotypic analyses of ovule development indicate targeted breeding for seed quality and yield, suggesting culturally driven selection was already established by the 15th century CE.