Speaker: Bibechana Adhikari, GDCB graduate student

Major: Plant Biology

Major professors: Emeritus Professor Phil Becraft, Professor Erik Vollbrecht

Department: Genetics, Development and Cell Biology

Title: "Study of gene co-expression network functioning in drought response during early endosperm development in maize"

Abstract: Cereal grains contribute greatly to food and are the primary source of nutrition for humans worldwide. The endosperm is the main storage tissue that is of primary value as a food. Early endosperm development is a crucial time that is affected by drought or other abiotic stresses, impacting grain quality and quantity of cereal crops. To better understand mechanisms of yield loss due to drought, we imposed drought stress during early endosperm development, and conducted transcriptome profiling and Gene Co-expression Network Analysis (GCNA). We found that drought stress affects the grain yield and size of the kernel and endosperm when induced early during development. We chose 12 modules for focused study based on their association with the treatments and were able to identify 313 hub genes divided among them. Hub genes were associated with diverse biological functions including autophagy, cell cycle, microtubules, and carbohydrate biosynthesis and are potentially key regulators in the co-expression networks functioning during early endosperm. Stress enhanced starch accumulation in endosperm, which is supported by altered carbohydrate metabolism seen in gene expression analysis. Stress also induced expression of the ABA-responsive RAB17-YFP reporter. Our study affirms that early onset of stress during endosperm development might have severe effects on development and eventually the grain yield in maize.