Interaction of auxin and strigolactone in the regulation of carpic dominance

点击翻译按钮获取中文摘要

BackgroundSeeds produced during plant reproduction are known to communicate with each other, and seeds in older/more vigorous fruits are able to limit or abort the development of new fruits/seeds. The mechanisms that drive this phenomenon ('carpic dominance') are poorly characterised, but preliminary data suggest the phytohormones strigolactone and auxin play key roles.Objectives1. Analyse the role of strigolactone and auxin in carpic dominance.2. Identify transcriptional responses that result in carpic dominance.3. Define environmental signals that modulate carpic dominance in crop species.NoveltyAlthough the phenomenon of carpic dominance is long-recognized, very little work has been undertaken, especially in the molecular genetic era. This project thus represents a highly novel area in plant developmental biology. TimelinessThere is a pressing need to increase crop yields to feed an expanding global population. This project is thus exceptionally timely, since carpic dominance is a major limit on seed set, and understanding it could unlock rapid increases in yield potential.Experimental ApproachTo define the role of strigolactone and auxin in carpic dominance, we will exploit existing molecular genetic tools in the model plant Arabidopsis, including auxin/strigolactone mutants and reporter lines. We will also develop tools in the crop plant tomato (which has strong carpic dominance) to perform live imaging of auxin/strigolactone dynamics during fruit development. We will use RNA-seq to identify transcriptional changes that occur in both dominant and dominated fruit/seeds during carpic dominance, and will then test the role of identified candidate genes in the phenomenon using reverse genetic analyses. We will also use both field and glasshouse experiments in the crop species oilseed rape (a close relative of Arabidopsis), to identify the environmental signals that modulate the extent of carpic dominance, and to transfer knowledge generated in Arabidopsis to field/agricultural contexts.This project aims to understand the biochemical, genetic and cellular mechanisms that form the basis of the carpic dominance phenomenon in plants. It is therefore deeply rooted in mechanistic biology at the molecular and cellular level. The project is an excellent fit with the remit of the agriculture and food security research area. Global food security will require increased yield from major crop species, and carpic dominance acts as a major limit on yield in many of these species. If we can understand the mechanistic basis of carpic dominance, we can breed crop species with reduced carpic dominance, which could result in a step-change in yield, without the need for more intensive inputs (e.g. fertilizer).