RP-HPLC and transcript profile indicate increased leaf caffeine in Coffea canephora plants by light

Avinash, Kumar and Simmi, P. S. and Gyanendra Kumar, Naik and Giridhar, P. (2015) RP-HPLC and transcript profile indicate increased leaf caffeine in Coffea canephora plants by light. Journal of Biology and Earth Sciences, 5 (1). pp. 1-9.

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Abstract

Light is a survival quotient for all photosynthetic plants and its reception is very complex due to direct regulation by photoreceptors and their downstream transcriptional factors or indirectly by circadian rhythm. Shade-grown coffee cultivation though less productive than the sun tolerant varieties, pose high potential as benefit to the environment. Other than high nutrient soil associated with shade-cultivated coffee, light is another important difference when compared to full sun cultivation practice. It is thus important to study if light has a role in accumulation of caffeine - the most undesired compound in coffee. Light irradiation of suspension cultures of Coffea arabica enhances caffeine content. However, no such study is available on whole plants, which are anticipated to act in accord with organismal homeostasis. Moreover, the promoter of theobromine synthase-like gene involved in caffeine biosynthesis carries several light responsive motifs. In this report, it is shown that in complete darkness the caffeine content in young leaves of 1 year old seedlings is very low (0.094±0.003 mg/100 mg tissue dw.). However, it increases to 5.9 folds within 6hrs of exposure to light. In addition, caffeine content drops (0.218±0.03 mg/100 mg tissue dw.) when light exposed plants are returned to complete dark. Transcript analysis further reveals that this difference is due to regulation of the caffeine biosynthetic genes. A further discussion to the effect of dark and light on levels of caffeine is also provided. Though cup quality of shade-grown coffee is indefinite, this study clearly demonstrates the role of light in regulation of caffeine biosynthesis.

Item Type:	Article
Uncontrolled Keywords:	Coffea; N-methyltransferase; Light; Transcript profiling; High Performance Liquid Chromatography
Subjects:	500 Natural Sciences and Mathematics > 04 Chemistry and Allied Sciences > 06 Chromatography 600 Technology > 07 Beverage Technology > 04 Coffee
Divisions:	Plant Cell Biotechnology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	19 May 2016 11:52
Last Modified:	19 May 2016 11:52
URI:	http://ir.cftri.res.in/id/eprint/12183

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