Functional Characterization of an Epigenetic Modifier that Controls Basal Endosperm Differentiation and Grain Filling in Maize

Abstract:
Efficient nutrient transfer into the maize endosperm is critical for grain filling and is mediated by the basal endosperm transfer layer (BETL), a specialized tissue whose differentiation is tightly regulated. Chopra lab is interested in characterizing the molecular role of Zmufo1; a gene previously known to epigenetically affect the expression of Zmp1 MYB gene regulating flavonoids accumulation in kernel pericarps. Loss-of-function and overexpression alleles of Zmufo1 both impair BETL formation, disrupt cell wall ingrowths, and lead to elevated reactive oxygen species and DNA damage. These phenotypes were significantly rescued by antioxidant treatments, underscoring the role of Zmufo1 in maintaining redox balance. Transcriptome analysis revealed widespread mis-regulation of redox-related genes, while increased histone acetyltransferase activity and altered chromatin structure in mutant lines indicated epigenetic mis-regulation. Epigenetic marks on Zmp1, were reduced in OEx Zmufo1 plants further supporting Zmufo1’s role in chromatin remodeling. Biochemical analysis revealed that ZmUFO1 harbors an intrinsically disordered region and undergoes liquid-liquid phase separation at low temperatures in vitro, forming β-sheet-rich aggregates. In vivo, ZmUFO1 localizes to the nucleus and nucleolar periphery and interacts with redox-sensitive nuclear proteins and chromatin remodelers. These findings establish Zmufo1 as a central regulator of BETL differentiation through redox and epigenetic mechanisms and raise intriguing questions about its phase separation behavior and temperature sensitivity.

About the Speaker:
Surinder Chopra received his MS (Genetics and Plant Breeding) from Punjab Agriculture University, India, and Ph.D. (in Molecular Genetics) from Vrije University, Brussels, Belgium. His post-doctoral fellowship in the laboratory of Prof. Thomas Peterson, Iowa State University, focused on maize genetics/epigenetics. He also served the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), an international research center of CGIAR as a legume breeder.
Surinder is currently a Professor in the Department of Plant Science at The Pennsylvania State University, USA, where he directs the maize and sorghum molecular genetics research programs and teaches graduate and undergraduate courses in Plant Genetics and Biotechnology. Surinder has mentored 22 graduate students as a major advisor and 32 graduate students as a thesis committee member/advisor. He has also mentored 63 undergraduate students, 5 post-doc scholars and interacted with 4 visiting scientists.

Currently, Surinder also directs the Graduate Studies program in Plant Science Department (Ag. and Environmental PL Sci)

Surinder’s national and international collaborative research program is both applied and basic leading to innovations. The research focus areas are:
1). Metabolic pathways regulation: role of microbiomes - from mechanisms and benefit to plant and animal health.
2). ROS and epigenetic regulatory mechanisms during maize kernel development
These research topics have been supported by grants from NSF and USDA-NIFA

Contact

  Charles Anderson
  cta3@psu.edu