Developmental Stages-Specific Response of Anise Plants to Laser-Induced Growth, Nutrients Accumulation, and Essential Oil Metabolism.

Mohammad K Okla,Nadi Awad Al-Harbi,Mohamed Abdel-Mawgoud,Salem Mesfir Al-Qahtani,Mohammed H Alruhaili,Wahidah H Al-Qahtani,Hamada Abdelgawad,Samy Selim,Saud A Alamri,Zahid Khorshid Abbas,Abdelrahim H A Hassan

doi:10.3390/plants10122591

Abstract

Compared to seeds and mature tissues, sprouts are well known for their higher nutritive and biological values. Fruits of Pimpinella anisum (anise) are extensively consumed as food additives; however, the sprouting-induced changes in their nutritious metabolites are hardly studied. Herein, we investigated the bioactive metabolites, phytochemicals, and antioxidant properties of fruits, sprouts (9-day-old), and mature tissue (5-week-old) of anise under laser irradiation treatment (He-Ne laser, 632 nm). Laser treatment increased biomass accumulation of both anise sprouts and mature plants. Bioactive primary (e.g., proteins and sugars) and secondary metabolites (e.g., phenolic compounds), as well as mineral levels, were significantly enhanced by sprouting and/or laser light treatment. Meanwhile, laser light has improved the levels of essential oils and their related precursors (e.g., phenylalanine), as well as enzyme activities [e.g., O–methyltransferase and 3-Deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS)] in mature tissues. Moreover, laser light induced higher levels of antioxidant and anti-lipidemic activities in sprouts as compared to fruits and mature tissues. Particularly at the sprouting stage, anise was more responsive to laser light treatment than mature plants.

Highlights

Sprouts are considered as rich sources of bioactive metabolites such as vitamins, minerals, and polyphenols, with various biological properties such as antioxidant and antitumor activities [1,2]
The absorption of laser light at a certain wavelength could activate the photosynthesis process and increase seed internal energy, which accelerates cell division and improve enzymatic activities [4,6,10]. This might include the induction of some phytohormones, such as indole-3-acetic acid (IAA), which is important for cell division and growth in germinating seeds [8]
The present results have revealed that laser light treatment significantly enhanced the amount of some detected bioactive primary and secondary metabolites in both sprouts and mature plants, in comparison to untreated controls (Table 1)

Summary

Introduction

Sprouts are considered as rich sources of bioactive metabolites such as vitamins, minerals, and polyphenols, with various biological properties such as antioxidant and antitumor activities [1,2]. The application of different techniques for enhancing the nutritional quality of sprouts and mature plants has been attracting much interest [3,4,5]. In this regard, the use of laser irradiation as a biophysical elicitor, has proved to increase plant growth and development, induce high content of phytochemicals and enhance plant productivity [4,6]. Previous reports have demonstrated the positive impact of laser light on increasing the quality and accumulation of bioactive metabolites of many plants, such as fennel, coriander, white lupine, faba bean, soybean, lemongrass sprouts, and buckwheat sprouts [4,8,9,10,11]

Methods

Results

Conclusion