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ARS Home » Pacific West Area » Albany, California » Plant Gene Expression Center » Research » Publications at this Location » Publication #358420

Research Project: Characterization of Plant Architectural Genes in Maize for Increased Productivity

Location: Plant Gene Expression Center

Title: Drawing a line: grasses and boundaries

item RICHARDSON, ANNIS - University Of California
item Hake, Sarah

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2018
Publication Date: 12/25/2018
Citation: Richardson, A., Hake, S.C. 2108. Drawing a line: grasses and boundaries. Plants. 8(1):4.

Interpretive Summary: The delineation between distinct populations of cells is an essential step in organ development. Boundary formation is necessary for the maintenance of the pluripotent meristematic cells in the shoot apical meristem (SAM) and the differentiation of developing organs. Boundaries are formed between whorls of organs (inter-whorl boundaries), between organs (intra-whorl boundaries) and within organs. Grasses have unique boundaries between the blade and sheath portion of the leaf. Many of the genes that function at these boundaries also regulate boundaries at the meristem.

Technical Abstract: Much of the research into the boundary gene regulatory network (GRN) has been carried out in the eudicot model Arabidopsis thaliana. This work has identified a dynamic network of hormone and gene interactions. Comparisons with other eudicot models such as tomato and pea, have shown key conserved nodes in the GRN and species-specific alterations, including the recruitment of the boundary GRN in leaf margin development. How boundaries are defined in monocots and in particular the grass family, which contains many of the world’s staple food crops, is not clear. Here we provide evidence for the grass boundary GRN during vegetative development. We particularly focus on the development of a grass-specific within-organ boundary, the ligule, which directly impacts leaf architecture. We also highlight key grass specific nodes in the known boundary GRNs, and the expansion of core gene families, which could allow for sub-functionalization within the grasses, perhaps explaining the lack of grass boundary mutants. Lastly, we consider how genome engineering and the use of natural diversity could be leveraged to influence key agronomic traits relative to leaf and plant architecture in the future, guided by knowledge of boundary GRNs.