Postdoctoral Research Associate University of Georgia Athens, Georgia
Body of Abstract: Blossom-end rot (BER) is a common physiological disorder that affects tomato and other vegetable crops. It can cause significant crop losses, ranging from 30% to 50%. Irregular watering conditions, particularly fluctuations in soil moisture levels, are linked to BER. Reactive Oxygen Species (ROS) are critical players in BER development which, combined with perturbed calcium homeostasis, greatly affect the severity of the disorder. The genetic aspects of the problem are complex, with multiple genes and environmental factors contributing to its development. Previous research identified several loci associated with BER, such as BER3.1 on chromosome (chr) 3, BER4.1 on chr4, and BER11.1 and BER11.2 on chr11, providing a starting point for further genetic investigations. In this study, both p<span style="color: black; mso-themecolor: text1;">rogeny testing and recombinant screening approaches were taken to further finemap BER4.1. We utilized two distinct genetic backgrounds, resulting in the identification of two overlapping genomic intervals. To identify differentially expressed genes, the RNA-seq approach was employed with RNA isolated from tissues that spanned BER onset. The highest number of differentially expressed genes were found at 10 DPA in the distal end pericarp tissue and included candidate genes involved in ROS as well as a sugar transporter. The most enriched GO terms of the differentially expressed genes were in the categories: response to chemical, phosphorylation, and response to abiotic stimulus. In summary, BER4.1 underlies a potential novel gene(s) controlling BER. The characterization of these candidate gene(s) may have an important impact on ameliorating BER not only in tomatoes but also in other vegetables suffering from BER. This research is supported by USDA AFRI grant 2020-67013-3091.