Type 2C protein phosphatase ABI1 is a negative regulator of strawberry fruit ripening

• Published in: Journal of experimental botany Vol. 64; no. 6; pp. 1677 - 1687
• Main Authors: Jia, Hai-feng, Lu, Dong, Sun, Jing-hua, Li, Chun-li, Xing, Yu, Qin, Ling, Shen, Yuan-yue
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press [etc.] 01.04.2013; Oxford University Press
• Subjects: Abscisic Acid; Agrobacterium - metabolism; amino acids; Arabidopsis; Base Sequence; Biological and medical sciences; complementary DNA; degreening; DNA, Complementary - genetics; DNA, Complementary - metabolism; Figs; Fragaria - enzymology; Fragaria - genetics; Fragaria - growth & development; Fruit - enzymology; Fruit - genetics; Fruit - growth & development; fruiting; Fruits; Fundamental and applied biological sciences. Psychology; gene expression; Gene Expression Profiling; Gene expression regulation; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Gene Silencing; Genes; Genes, Plant; Messenger RNA; Molecular Sequence Data; Northern blotting; Open Reading Frames; Phosphatases; Phosphoprotein Phosphatases - genetics; Phosphoprotein Phosphatases - metabolism; Phytopathology. Animal pests. Plant and forest protection; Plant physiology and development; Plant Proteins - genetics; Plant Proteins - metabolism; Protein Phosphatase 2C; quantitative polymerase chain reaction; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Regulator genes; RESEARCH PAPER; Ripening; RNA; RNA, Messenger - analysis; RNA, Messenger - genetics; RNA, Plant - analysis; RNA, Plant - genetics; Signal Transduction; Strawberries; tobacco; transcription (genetics); Transcription, Genetic; virus-induced gene silencing (VIGS); Plant pathogen; Enzyme; Phosphoprotein phosphatase; Abscisic acid (ABA); Phosphoric monoester hydrolases; Gene overexpression; Esterases; Regulator; Virus; Ripening; Gene silencing; Tobravirus; overexpression; type 2C protein phosphatase ABI1; Sesquiterpenes; Strawberry; Botany; strawberry fruit ripening; Abscisic acid; Hydrolases; Plant growth substance; Tobacco rattle virus
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/ert028

Although a great deal of progress has been made toward understanding the role of abscisic acid (ABA) in fruit ripening, many components in the ABA signalling pathway remain to be elucidated. Here, a strawberry gene homologous to the Arabidopsis gene ABI1, named FaABI1, was isolated and characterized. The 1641bp cDNA includes an intact open reading frame that encodes a deduced protein of 546 amino acids, in which putative conserved domains were determined by homology analysis. Transcriptional analysis showed that the levels of FaABI1 mRNA expression declined rapidly during strawberry fruit development as evidenced by real-time PCR, semi-quantitative reverse transcription–PCR, and northern blotting analyses, suggesting that the Ser/Thr protein phosphatase PP2C1 encoded by FaABI1 may be involved in fruit ripening as a negative regulator. The results of Tobacco rattle virus-induced gene silencing and PBI121 vector-mediated overexpression suggested that the down- and up-regulation of FaABI1 mRNA expression levels in degreening strawberry fruit could promote and inhibit ripening, respectively. Furthermore, alteration of FaABI1 expression could differentially regulate the transcripts of a set of both ABA-responsive and ripening-related genes, including ABI3, ABI4, ABI5, SnRK2, ABRE1, CHS, PG1, PL, CHI, F3H, DFR, ANS, and UFGT. Taken together, the data provide new evidence for an important role for ABA in regulating strawberry fruit ripening in the processes of which the type 2C protein phosphatase ABI1 serves as a negative regulator. Finally, a possible core mechanism underlying ABA perception and signalling transduction in strawberry fruit ripening is discussed.