The molecular dissection of seed quality
The yield and economic success of horticultural crops depends to a large degree on the quality of the seed used to grow these crops. Seed quality or seed performance is the resultant of a series of complex processes that are involved in the transition from a developing seed to a growing plant. Examples of the processes involved are: embryo formation, germination, growth of the seedling and its tolerance to stress.
Seed quality attributes include dormancy, germination (rate and uniformity), seed and seedling vigour (germination/growth under stress conditions), seedling dry weight, normal embryo- and seedling morphology, as well as the ability to develop into a normal plant. Seed quality is largely established during seed development and maturation, as a result of, often complex, interactions between the genome and the environment. This mechanism is part of the normal adaptation of plants to a varying environment and is aimed at maximizing the probability of successful offspring.
The molecular-genetic dissection of these seed processes and their relationship with seed and seedling phenotypes will identify the regulatory genes and signaling pathways involved and, thus, provide the means to predict and enhance seed quality.
In this project we employ forward genetic screening by performing quantitative trait loci (QTL) mapping to identify genomic regions (loci) in tomato and Arabidopsis recombinant inbred line (RIL) and near isogenic line (NIL) populations that are associated with a broad range of seed quality attributes. The RILs are further phenotyped by transcriptional-, metabolite- and hormone profiling, using state-of-the-art technology. This combined use of physiology, genetics and genomics, followed by advanced data analysis and in combination with a ‘likely candidate gene approach’ will relatively quickly identify genes that are responsible for quality related traits of seed and seedling. Subsequent analysis of the relevant genes by reverse genetics, using knock-out and overexpression mutants, will be employed to unambiguously confirm their function.