Anatomical, computational and molecular analyses of vascularization in coffee peduncles of reproductive buds and fruits future perspectives for the Coffea arabica L.

Abstract

Coffee beans are an agricultural commodity predominantly cultivated in tropical regions, supporting the livelihoods of millions. The flowering process of coffee plants is indispensable for bean development but often suffers from unevenness, resulting in inconsistent fruit maturation. This issue is particularly pronounced in Brazil, where mechanized harvesting blends unripe and ripe beans, negatively affecting quality. Moreover, non-uniform flowering complicates pest and disease management. Given the sensitivity of floral buds to water availability, understanding vascular development in reproductive organs, especially peduncles that connect inflorescences to branches, is necessary. Our study investigates the anatomical and molecular aspects of vascular development in coffee's reproductive organs through a combination of anatomical, molecular, and computational analyses. We performed in silico analyses to identify orthologous key genes involved in vascular development, such as Class III Homeodomain-Leucine Zipper (HB Zip III) and OCTOPUS (OPS) from Arabidopsis thaliana, and VASCULAR-RELATED NAC-DOMAIN7 (VND7) from Populus trichocarpa. Subsequently, we quantified the expression levels of these orthologous group members (HB, OPS, and VND7). Finally, we combined in silico analyses with a comprehensive study of peduncle vasculature across 16 stages, encompassing the development of flower buds, flowers, and fruits. Our findings deepen the understanding of vascular development in coffee, providing insights that could enhance cultivation practices by optimizing conditions for flowering and fruiting. This study aims to fill the knowledge gap regarding the anatomical and vascular development of coffee peduncles, offering a comprehensive view of their role in supporting the growth and maturation of coffee flowers and fruits.