Prof. Adrienne Roeder
Date & Location: October 30, 2017, at 4p; Room 1200 Molecular Plant Sciences Building
Subject: Plant Cell Division and Cell Size, especially in Flower Development
About the Speaker
University: Cornell University
Research Interests: Size is a fundamental characteristic of every organism; animals from mouse to elephant and plants from Wolfia, the smallest flowering plant, to the towering giant sequoia trees must establish and maintain proper organ size and shape. Peter Lawrence has remarked that size “is the material that evolution largely works on” (Vogel, 2013).
How an organ senses its size and determines when to stop growing is one of the biggest remaining mysteries in developmental biology. Developmental processes regulating size and shape are remarkably reliable in producing nearly invariant organs within a species. For example, the two arms of a person match in length with an accuracy of 0.2% (Wolpert, 2010), and Arabidopsis floral organs are strikingly uniform in size and shape (Mizukami, 2001).
The size of an organ is determined by the number and size of its cells. Confoundingly, the behavior of these cells is often variable and unpredictable. Equivalent neighboring plant cells grow at markedly different rates in several developing tissues (Armour et al., 2015; Elsner et al., 2012; Kierzkowski et al., 2012; Tauriello et al., 2015; Uyttewaal et al., 2012); although at later stages of development, growth may become more uniform (Zhang et al., 2011). Similarly, neighboring cells have different constriction rates during Drosophila gastrulation (Martin et al., 2009).
The research in the Roeder laboratory falls at the intersection of cell biology and developmental biology, focusing on two interrelated fundamental questions: (1) how are variable cell sizes produced during development and (2) how do reproducible organ sizes and shapes emerge from the variable growth of their cells? The theme emerging from the lab’s research is the importance of cellular variability in plant development. This principle is surprising because biologists generally think of development as being a highly regulated and reproducible process, where variability must be suppressed. Instead we are finding that the plant utilizes this variability to produce regularity.