DELAY OF GERMINATION 1-LIKE 4 acts as an inducer of seed reserve accumulation

More than 70% of global food supply depends on seeds. The major seed reserves, such as proteins, lipids, and polysaccharides, are produced during seed maturation. Here, we report that DELAY OF GERMINATION 1-LIKE 4 (DOGL4) is a major inducer of reserve accumulation during seed maturation. The DOGL family proteins are plant-specific proteins of largely unknown biochemical function. DOGL4 shares only limited homology in amino acid sequence with DOG1, a major regulator of seed dormancy. DOGL4 was identified as one of the outstanding abscisic acid (ABA)-induced genes in our RNA sequencing analysis, whereas DOG1 was not induced by ABA. Induction of DOGL4 caused the expression of 70 seed maturation-specific genes, even in germinating seeds, including the major seed reserves ALBUMIN, CRUCIFERIN and OLEOSIN. Although DOG1 affects the expression of many seed maturation genes, the major seed reserve genes induced by DOGL4 are not altered by the dog1 mutation. Furthermore, the reduced dormancy and longevity phenotypes observed in the dog1 seeds were not observed in the dogl4 mutants, suggesting that these two genes have limited functional overlap. Taken together, these results suggest that DOGL4 is a central factor mediating reserve accumulation in seeds, and that the two DOG1 family proteins have diverged over the course of evolution into independent regulators of seed maturation, but retain some overlapping function.</p

Sahelian smallholders’ varietal mixtures reconcile yield and agrobiodiversity conservation

International audienceIn the current setting, marked by the major challenges of growing food demand and climate change impacts, the ability of sub-Saharan agriculture to meet population needs depends on the resilience and adaptation capacity of this system. Using agrobiodiversity to promote agricultural sustainability is a strategy that has garnered much attention lately. Research suggests that mixing species or varieties within crop fields could increase the yield and/or stability. This mixing is also geared towards the conservation of crop diversity while ensuring that the various associated products and services will be available at the farm level. Few recent research studies have highlighted the benefits of varietal mixtures for Africa. This lack of research is a concern, given that this continent is considered to be highly vulnerable to climate change. This study was carried out to test whether plots with varietal mixtures would outperform monovarietal plots in terms of yield and pathogen regulation under smallholder farming conditions in Senegal. Together with farmers, we conducted 30 experiments in which mixtures of early-and late-flowering pearl millet landraces were grown in these farmers' fields, while monitoring their low input management. We noted a significant positive effect of varietal mixtures on grain yield (mean gain of 63 § 31.5 kg ha À1 for mixture plots, p = 0.046) with a relative yield total (RYT) averaging 1.87 § 0.94. Both early-and late-flowering landraces benefited from mixtures, with a greate