Phylogeny and expression profiling of CAD and CAD-like genes in hybrid Populus (P. deltoides × P. nigra): evidence from herbivore damage for subfunctionalization and functional divergence

BMC Plant Biology

Research Article

Agnieszka Bagniewska-Zadworna¹  John E Carlson²  Abdelali Barakat²  Christopher J Frost³ 

[1] Department of General Botany, Institute of Experimental Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznań, Poland;The School of Forest Resources, and The Huck Institutes of the Life Sciences, Pennsylvania State University, 324 Forest Resources Building, 16802, University Park, PA, USA;The School of Forest Resources, and The Huck Institutes of the Life Sciences, Pennsylvania State University, 324 Forest Resources Building, 16802, University Park, PA, USA;Center for Chemical Ecology, Pennsylvania State University, 16802, University Park, PA, USA;

关键词: Lymantria Dispar;    Normal Growth Condition;    Lignin Biosynthesis;    Cinnamyl Alcohol Dehydrogenase;    Preferential Expression;   

DOI  :  10.1186/1471-2229-10-100

 received in 2010-01-05, accepted in 2010-05-28,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundCinnamyl Alcohol Dehydrogenase (CAD) proteins function in lignin biosynthesis and play a critical role in wood development and plant defense against stresses. Previous phylogenetic studies did not include genes from seedless plants and did not reflect the deep evolutionary history of this gene family. We reanalyzed the phylogeny of CAD and CAD-like genes using a representative dataset including lycophyte and bryophyte sequences. Many CAD/CAD-like genes do not seem to be associated with wood development under normal growth conditions. To gain insight into the functional evolution of CAD/CAD-like genes, we analyzed their expression in Populus plant tissues in response to feeding damage by gypsy moth larvae (Lymantria dispar L.). Expression of CAD/CAD-like genes in Populus tissues (xylem, leaves, and barks) was analyzed in herbivore-treated and non-treated plants by real time quantitative RT-PCR.ResultsCAD family genes were distributed in three classes based on sequence conservation. All the three classes are represented by seedless as well as seed plants, including the class of bona fide lignin pathway genes. The expression of some CAD/CAD-like genes that are not associated with xylem development were induced following herbivore damage in leaves, while other genes were induced in only bark or xylem tissues. Five of the CAD/CAD-like genes, however, showed a shift in expression from one tissue to another between non-treated and herbivore-treated plants. Systemic expression of the CAD/CAD-like genes was generally suppressed.ConclusionsOur results indicated a correlation between the evolution of the CAD gene family and lignin and that the three classes of genes may have evolved in the ancestor of land plants. Our results also suggest that the CAD/CAD-like genes have evolved a diversity of expression profiles and potentially different functions, but that they are nonetheless co-regulated under stress conditions.

【 授权许可】

CC BY   
© Barakat et al; licensee BioMed Central Ltd. 2010