Evolution of Development and Physiology
Lehti-Shiu, Melissa , Shiu, Shin-Han .
Evolutionary History and Stress Responsiveness of Plant Receptor-Like Kinases.
The Receptor-Like Kinase (RLK)/Pelle family is one of the largest plant gene families with >600 and >1200 members in Arabidopsis thaliana and rice, respectively. To uncover the evolutionary history of RLKs, we conducted a phylogenetic analysis of the kinase superfamily in A. thaliana, rice, poplar, moss (Physcomitrella patens) and the unicellular algae, Chlamydomonas reinhardtii. We found that poplar and moss have 1192 and 338 RLK/Pelle genes, respectively; however, none were found in algae. Expansion of this family has occurred independently in all land plant lineages, indicating its importance to land plants in general. In addition to large family size, another important feature of RLKs is their diversity in domain organization. Out of 25 types of RLKs with distinct domain configurations, 17 can be found in moss, indicating that most of the receptor configurations were established early in land plant evolution. Some highly conserved RLK types contain extracellular domains capable of interacting with fungi and bacteria, indicating the important roles RLKs played in stress responses in the evolution of land plants. To determine the types of stresses that RLKs are responsive to, we used AtGenExpress stress array data to compare the expression patterns of RLKs. We found that RLKs that have undergone recent expansion are more likely to be induced by stress. Furthermore, this relationship can be attributed mostly to the expansion of tandem duplicated RLKs. We also observed that different RLK/Pelle subfamilies differ in the breadth of responsiveness to stress. Together these results point to the presence of strong selection pressure for expanding the plant RLK/Pelle family, potentially leading to improved stress responsiveness in plants.
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1 - Michigan State University, Plant Biology, S-308 Plant Biology Bldg, East Lansing, MI, 48824, USA
2 - Michigan State University, Plant Biology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM