Impact of soil field water capacity on secondary metabolites, phenylalanine ammonia-lyase (PAL), maliondialdehyde (MDA) and photosynthetic responses of Malaysian kacip fatimah (Labisia pumila Benth).

Hawa Z. E. Jaafar,Mohd Hafiz Ibrahim,Nur Farhana Mohamad Fakri

doi:10.3390/molecules17067305

Hawa Z. E. Jaafar, Mohd Hafiz Ibrahim + Show 1 more

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https://doi.org/10.3390/molecules17067305

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Journal: Molecules (Basel, Switzerland)	Publication Date: Jun 13, 2012
Citations: 144	License type: CC BY 3.0

Affiliation: Universiti Putra Malaysia

Abstract

A randomized complete block design 2 × 4 experiment was designed and conducted for 15 weeks to characterize the relationships between production of total phenolics, flavonoid, anthocyanin, leaf gas exchange, total chlorophyll, phenylalanine ammonia-lyase (PAL) and malondialdehyde (MDA) activity in two varieties of Labisia pumila Benth, namely the var. alata and pumila, under four levels of evapotranspiration replacement (ER) (100%; well watered), (75%, moderate water stress), (50%; high water stress) and (25%; severe water stress). The production of total phenolics, flavonoids, anthocyanin, soluble sugar and relative leaf water content was affected by the interaction between varieties and SWC. As the ER levels decreased from 100% to 25%, the production of PAL and MDA activity increased steadily. At the highest (100%) ER L. pumila exhibited signiﬁcantly higher net photosynthesis, apparent quantum yield, maximum efficiency of photosystem II (fv/fm) and lower dark respiration rates compared to the other treatment. The production of total phenolics, flavonoids and anthocyanin was also found to be higher under high water stress (50% ER replacement) compared to severe water stress (25% ER). From this study, it was observed that as net photosynthesis, apparent quantum yield and chlorophyll content were downregulated under high water stress the production of total phenolics, flavonoids and anthocyanin were upregulated implying that the imposition of high water stress can enhance the medicinal properties of L. pumila Benth.

Highlights

There has been an increased interest in understanding the mechanism of plant acclimation to environmental stresses [1,2,3]
The present study indicated that when production of total chlorophyll was down-regulated under water stress condition it may be the signal for increased production of total phenolics, flavonoids and anthocyanins in L. pumila
Our results indicate that the manipulation of soil water capacity may be an effective method to increase the expression of secondary metabolites compounds in L. pumila

Summary

Introduction

There has been an increased interest in understanding the mechanism of plant acclimation to environmental stresses [1,2,3]. Recent advances in plant sciences have led to great interest in increasing the production of plant secondary metabolites for their medicinal and aromatic uses [6]. A better understanding of the environmental influences on the regulation of plant secondary metabolism is advantageous for the cultivation of medicinal plants such as Labisia pumila Benth [7]. The other uses of this herb are in treatments for dysentery, dysmenorrhea, flatulence, and gonorrhea [9] This herb has received a lot of attention among scientists, herbalists and the pharmacy industry in Malaysia due to its therapeutic effects and high total contents of phenolic and flavonoid compounds. These polyphenolic compounds have received considerable interest because of their protective role against cancer and heart disease, attributed to their antioxidative activity against reactive oxygen species, which was reported to be higher than that of vitamins C and E [10]

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Results

Conclusion