Identification of differentially expressed genes in pistils from self-incompatible Citrus reticulata by suppression subtractive hybridization.
Self-incompatibility (SI) is one important factor that can result in Citrus seedlessness. However, the molecular mechanism of SI in Citrus is not clear yet. To isolate the pistil's SI-related genes, a suppression subtractive hybridization library was constructed using mature pistils of 'Wuzishatangju' mandarin (SI) as the tester and mature pistils of 'Shatangju' mandarin (self-compatibility, SC) as the driver. 229 differentially expressed cDNA clones from 967 positive clones were sequenced and identified. Differentially expressed ESTs are possibly involved in the SI reaction of 'Wuzishatangju' through a regulating signaling pathway, serine/threonine phosphatase activity, receptor kinase, embryonic development, gibberellin stimulus, or transcription. 11 out of 36 SI candidate genes displayed different expression patterns in various tissues and stages after self- and cross-pollination of 'Wuzishatangju'. The expression of CaBP (WY65), a senescence-protease (WY372), an unknown gene (WY283), and a WRKY (WY17) were up-regulated in the styles of 'Wuzishatangju' while higher expression of WY190 was observed in styles of 'Shatangju'. Highest expression levels of WY65, WY372, an annexin (WY598), the zinc-finger protein (WY376), a C2-protein (WY291), and an unknown gene (WY318) were detected in styles at 3 days after self-pollination of 'Wuzishatangju' while lowest levels were observed in styles at 3 days after cross-pollination of 'Wuzishatangju' × 'Shatangju'. The potential involvement of these genes in the SI reaction is discussed.
College of Horticulture, South China Agricultural University, Guangdong 510642, People's Republic of China. hxmrain@163.com
Hongxia
H
Miao
Yonghua
Y
Qin
Jaime A Teixeira
JA
da Silva
Zixing
Z
Ye
Guibing
G
Hu
D002957:Citrus / Q000235:genetics*; D019295:Computational Biology; D035264:Flowers / Q000235:genetics*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D006824:Hybridization, Genetic; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D054817:Pollination / Q000235:genetics*