Journal Article

Multiple tandem duplication of the phenylalanine ammonia-lyase genes in Cucumis sativus L

Shang, Qing-Mao, Li, Liang, Dong, Chun-Juan

2012

Overview

Phenylalanine ammonia-lyase (PAL) is the first entry enzyme of the phenylpropanoid pathway, and therefore plays a key role in both plant development and stress defense. In many plants, PAL is encoded by a multi-gene family, and each member is differentially regulated in response to environmental stimuli. In the present study, we report that PAL in cucumber (Cucumis sativus L.) is encoded for by a family of seven genes (designated as CsPAL1-7). All seven CsPALs are arranged in tandem in two duplication blocks, which are located on chromosomes 4 and 6, respectively. The cDNA and protein sequences of the CsPALs share an overall high identity to each other. Homology modeling reveals similarities in their protein structures, besides several slight differences, implying the different activities in conversion of phenylalanine. Phylogenic analysis places CsPAL1-7 in a separate cluster rather than clustering with other plant PALs. Analyses of expression profiles in different cucumber tissues or in response to various stress or plant hormone treatments indicate that CsPAL1-7 play redundant, but divergent roles in cucumber development and stress response. This is consistent with our finding that CsPALs possess overlapping but different cis-elements in their promoter regions. Finally, several duplication events are discussed to explain the evolution of the cucumber PAL genes.

• Publisher: Springer-Verlag,Springer,Springer Nature B.V
• Subject: Abscisic Acid - pharmacology / Agriculture / Amino Acid Sequence / amino acid sequences / Ammonia / Biological and medical sciences / Biomedical and Life Sciences / chromosome 4 / Chromosomes / complementary DNA / Cucumbers / Cucumis sativus / Cucumis sativus - drug effects / Cucumis sativus - enzymology / Cucumis sativus - genetics / Cucumis sativus - physiology / DNA, Plant - chemistry / DNA, Plant - genetics / Ecology / Environmental effects / Enzymes / Evolution / Evolutionary genetics / Forestry / Fundamental and applied biological sciences. Psychology / Gene Duplication / Gene Expression Regulation, Enzymologic - genetics / Gene Expression Regulation, Plant - genetics / Genes / Genomes / Homology / Hormones / Life Sciences / Messenger RNA / Models, Molecular / Molecular Sequence Data / Multigene Family / Open reading frames / Organ Specificity / Original Article / Phenylalanine / Phenylalanine ammonia-lyase / Phenylalanine Ammonia-Lyase - genetics / phenylpropanoids / Phylogeny / Plant Components, Aerial - drug effects / Plant Components, Aerial - enzymology / Plant Components, Aerial - genetics / Plant Components, Aerial - physiology / plant development / Plant Growth Regulators - physiology / plant hormones / Plant Proteins - genetics / Plant roots / Plant Roots - drug effects / Plant Roots - enzymology / Plant Roots - genetics / Plant Roots - physiology / Plant Sciences / plant stress / Plants / promoter regions / Promoter Regions, Genetic - genetics / Promoters / Protein structure / Proteins / Seedlings / Seedlings - drug effects / Seedlings - enzymology / Seedlings - genetics / Seedlings - physiology / Sequence Alignment / Sequence Analysis, DNA / Stress / stress response / Stress, Physiological / Tandem Repeat Sequences / Vegetables