Expression of CsSEF1 gene encoding putative CCCH zinc finger protein is induced by defoliation and prolonged darkness in cucumber fruit
- 399 Downloads
To find a marker gene for photoassimilate limitation in cucumber fruit, genes induced in young fruit by total defoliation were cloned using the subtraction method. Almost every clone matched perfectly to a member of cucumber unigene ver. 3 of the Cucurbit Genomics Database. From the clones obtained, six genes were selected and the effect of defoliation on their expression was analyzed. In particular, expression of a gene that is highly homologous to the cucumber gene CsSEF1 (CAI30889) encoding putative CCCH zinc finger protein, which is reported to be induced at somatic embryogenesis in suspension culture, was enhanced by the treatment by about 50 times. The sequencing of the full-length cDNA and BLAST search in the Cucurbit Genomics Database indicated that our cloned gene is identical to CsSEF1. In control fruit, the expression of CsSEF1 did not change markedly in terms of development. By contrast, the expression of CsSEF1 was enhanced by prolonged darkness at the transcript level. This increase in the expression of CsSEF1 was temporally correlated with the decline in the fruit respiration rate. In mature leaves under prolonged darkness, enhanced expression was observed in the asparagine synthetase gene, but not in CsSEF1. These results suggest that the asparagine synthetase gene can be a good marker for sugar starvation and that CsSEF1 might be involved in the signal transduction pathway from photoassimilate limitation to growth cessation in cucumber fruit.
KeywordsCsSEF1 Cucumber Fruit growth Photoassimilate Respiration Tandem CCCH zinc finger
Days after anthesis
Quantitative reverse transcriptase–polymerase chain reaction
Rapid amplification of cDNA ends
Tandem CCCH zinc finger
We thank Dr. Yoshiteru Sakata of the Institute of Vegetable and Tea Science, National Agriculture and Food Research Organization, for kindly offering the seeds of the cucumber cultivar ‘Tokiwa’. This work was supported by Grant-in-Aid for Scientific Research (C) (22580285) on Priority Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan to TA.
- Ho LC, Grange RI, Picken AJ (1987) An analysis of the accumulation of water and dry matter in tomato fruit. Plant Cell Environ 10:157–162Google Scholar
- Kato T, Oda H (1977) Studies on the control of physiological disorders in fruit vegetable crops under plastic films. VIII. On the occurrence of abnormal fruits in cucumber plants. (II) On the development of carrot type and bottle gourd type fruits, so-called sakibosori and shiributo fruits in Japan. (Japanese text with English abstract) Res Rep Kochi Univ 26 (Agric Sci):175–182Google Scholar
- Nobel PS (2009) Physicochemical and environmental plant physiology. Academic Press, London, pp 439–505Google Scholar
- Pharr DM, Sox HN, Smart EL, Lower RL (1977) Identification and distribution of soluble saccharides in pickling cucumber plants and their fate in fermentation. J Amer Soc Hort Sci 102:406–409Google Scholar
- R Development Core Team (2011) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org/
- Tazuke A, Sakiyama R (1991) Relationships between growth in volume and respiration of cucumber fruit attached on the vine. J Japan Soc Hort Sci 59:745–750Google Scholar