Parallel expression evolution of oxidative stress-related genes in fiber from wild and domesticated diploid and polyploid cotton (<it>Gossypium</it>)

• Main Authors: Mittler Ron, Flagel Lex, Hovav Ran, Chaudhary Bhupendra, Wendel Jonathan F
• Format: Article
• Language: English
• Published: BMC 2009-08-01
• Series: BMC Genomics
• Online Access: http://www.biomedcentral.com/1471-2164/10/378

<p>Abstract</p> <p>Background</p> <p>Reactive oxygen species (ROS) play a prominent role in signal transduction and cellular homeostasis in plants. However, imbalances between generation and elimination of ROS can give rise to oxidative stress in growing cells. Because ROS are important to cell growth, ROS modulation could be responsive to natural or human-mediated selection pressure in plants. To study the evolution of oxidative stress related genes in a single plant cell, we conducted comparative expression profiling analyses of the elongated seed trichomes ("fibers") of cotton (<it>Gossypium</it>), using a phylogenetic approach.</p> <p>Results</p> <p>We measured expression changes during diploid progenitor species divergence, allopolyploid formation and parallel domestication of diploid and allopolyploid species, using a microarray platform that interrogates 42,429 unigenes. The distribution of differentially expressed genes in progenitor diploid species revealed significant up-regulation of ROS scavenging and potential signaling processes in domesticated <it>G. arboreum</it>. Similarly, in two independently domesticated allopolyploid species (<it>G. barbadense </it>and <it>G. hirsutum</it>) antioxidant genes were substantially up-regulated in comparison to antecedent wild forms. In contrast, analyses of three <it>wild </it>allopolyploid species indicate that genomic merger and ancient allopolyploid formation had no significant influences on regulation of ROS related genes. Remarkably, many of the ROS-related processes diagnosed as possible targets of selection were shared among diploid and allopolyploid cultigens, but involved different sets of antioxidant genes.</p> <p>Conclusion</p> <p>Our data suggests that parallel human selection for enhanced fiber growth in several geographically widely dispersed species of domesticated cotton resulted in similar and overlapping metabolic transformations of the manner in which cellular redox levels have become modulated.</p>