title: Characterization and functional analysis of GhRDR6, a novel RDR6 gene from cotton (Gossypium hirsutum L.).
abstract: RDR6 (RNA-dependent RNA polymerase 6) is not only involved in virus resistance but also plays an important role in natural plant development. In the present study, a novel RDR gene, named GhRDR6 (Gossypium hirsutum RDR6), was isolated from cotton (G. hirsutum L.). Alignment and evolutionary relationship analyses showed that GhRDR6 was more closely related to RDR6 than to other RDRs. Expression analysis indicated that this single-copy gene is constitutively expressed in the roots, stems and leaves. Semi-quantitative RT-PCR (reverse transcription-PCR) showed that GhRDR6 was up-regulated by the application of various phytohormones, including MeJA [methyl JA (jasmonate)], ABA (abscisic acid), JA, α-naphthylacetic acid, gibberellins and ET (ethylene). In addition, GhRDR6 expression increased in response to wounding, cold (4°C) and NaCl treatments, but not by drought. Furthermore, overexpression of GhRDR6 in transgenic Nicotiana benthamiana plants resulted in root lengths longer than the wide-type during the seeding stage. Interestingly, the GhRDR6-overexpressing plants displayed reduced tolerance to oxidative damage, resulting in reduced ABA-sensitivity, but they tolerated freezing. Moreover, resistance to potato virus Y was enhanced in transgenic N. benthamiana plants. These results suggest that GhRDR6 may play an important role in plant defence responses and a pivotal role in plant development.
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, People's Republic of China.
authors.forename: Mian
authors.initials: M
authors.lastname: Wang
authors.forename: Shanwei
authors.initials: S
authors.lastname: Li
authors.forename: Haifang
authors.initials: H
authors.lastname: Yang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Gao
authors.forename: Changai
authors.initials: C
authors.lastname: Wu
authors.forename: Xingqi
authors.initials: X
authors.lastname: Guo
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D055864:Droughts; D005615:Freezing; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D003368:Gossypium / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D012324:RNA-Dependent RNA Polymerase