Functional analysis of GbAGL1, a D-lineage gene from cotton (Gossypium barbadense)

• Published in: Journal of experimental botany Vol. 61; no. 4; pp. 1193 - 1203
• Main Authors: Liu, Xiang, Zuo, Kai-jing, Xu, Jie-ting, Li, Ying, Zhang, Fei, Yao, Hong-yan, Wang, Yue, Chen, Yu, Qiu, Cheng-xiang, Sun, Xiao-fen, Tang, Ke-xuan
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.02.2010
• Subjects: AG-subfamily; Amino Acid Sequence; Arabidopsis; Biological and medical sciences; Calyx; complementation test; Cotton; D-lineage gene; Developmental biology; fibre development; Flower buds; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Genes; Gossypium - chemistry; Gossypium - genetics; Gossypium - growth & development; Gossypium - metabolism; Gossypium barbadense; Molecular Sequence Data; over-expression; Ovule - chemistry; Ovule - genetics; Ovule - growth & development; Ovule - metabolism; ovule development; Ovules; Phylogeny; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; Plants - chemistry; Plants - classification; Plants - genetics; Research Papers; RNA; Seeds; Sequence Homology, Amino Acid; Transgenic plants; fibre development; complementation test; over-expression; D-lineage gene; AG-subfamily; ovule development; Malvaceae; Gossypium barbadense; Arabidopsis; Fiber; Functional analysis; Fiber crop; Arabidopsis thaliana; Gene; Cruciferae; Dicotyledones; Angiospermae; Botany; Ovule; Development; Spermatophyta; Complementation; Experimental plant
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/erp388

Cotton fibres originate from the outer ovule integument and D-lineage genes are essential for ovule development and their roles can be described by the 'ABCDE' model of flower development. To investigate the role of D-lineage genes during ovule and fibre development, GbAGL1 (GenBank accession number: FJ198049) was isolated from G. barbadense by using the SMART RACE strategy. Sequence and phylogenetic analyses revealed that GbAGL1 was a member of the D-lineage gene family. Southern blot analysis showed that GbAGL1 belonged to a low-copy gene family. Semi-quantitative RT-PCR and RNA in situ hybridization analyses revealed that the GbAGL1 gene in G. barbadense was highly expressed in whole floral bud primordia and the floral organs including ovules and fibres, but the signals were barely observed in vegetative tissues. GbAGL1 expression increased gradually with the ovule developmental stages. Over-expression of GbAGL1 in Arabidopsis caused obvious homeotic alternations in the floral organs, such as early flowering, and an extruded stigma, which were the typical phenotypes of the D-lineage gene family. In addition, a complementation test revealed that GbAGL1 could rescue the phenotypes of the stk mutant. Our study indicated that GbAGL1 was a D-lineage gene that was involved in ovule development and might play key roles in fibres development.