Genome-wide association of stomatal density trait in tropical tree, Shorea leprosula (Dipterocarpaceae)

Stomata play a vital role in plant functioning by allowing gas exchange duringphotosynthesis and regulating water movement via transpiration. Many studies havebeen conducted on stomata traits (density) in order to understand the molecular basisof drought tolerance in plants. However, most of the studies were focused on modelspecies or agriculturally important crops and little is known about the molecularmechanisms underlying drought response of tropical tree species. We investigated theunderlying genetics of stomata density in Shorea leprosula, a common light redmeranti tree in Southeast Asian rainforests. We estimated a relatively high heritability(h2 = 0.48) from 104 half-sib families, suggesting strong genetic influence on thedevelopment of stomata in Shorea leprosula. By performing a genome-wideassociation study, we identified significant putative SNPs within two candidate genemodels (g16569 and g13880) homologous to the stomatal development (MPK6;AT2G43790) and function (CHC1; AT3G11130) in Arabidopsis thaliana. These twoputative genes could be potentially used as molecular markers in screening of treestolerant to drought stress with the ultimate goal to improve future planting strategies.