Effect of Heat Stress on Sargassum fusiforme Leaf Metabolome

Lijie Liu,Lidong Lin

doi:10.1007/s12374-020-09247-5

Abstract

Temperature is a major environmental factor affecting the growth, development, and productivity of Sargassum fusiforme. We aimed to assess the metabolic processes and regulatory mechanisms in S. fusiforme during a 7-day high-temperature (27 °C and 32 °C) experiment. Changes in chlorophyll content and electrolyte leakage after high-temperature treatment were investigated. Metabolic changes in the leaves of S. fusiforme were analysed using gas chromatography–mass spectrometry. High temperatures suppressed chlorophyll content and increased electrolyte leakage. Further, a strong modulation of various metabolisms was observed: organic acids, amino acids, sugars or sugar alcohols, esters, and amines. These metabolisms were significantly enriched in ten pathways under the 27 °C treatment: aminoacyl-tRNA biosynthesis; glycine, serine, and threonine metabolism; alanine, aspartate, and glutamate metabolism; valine, leucine, and isoleucine biosynthesis; cyanoamino acid metabolism; cysteine and methionine metabolism; arginine and proline metabolism; tyrosine metabolism; citrate cycle (TCA cycle); and glucosinolate biosynthesis. The various metabolisms significantly enriched seven pathways under the 32 °C treatment, namely, alanine, aspartate, and glutamate metabolism; aminoacyl-tRNA biosynthesis; phenylalanine metabolism; tyrosine metabolism; arginine and proline metabolism; nitrogen metabolism; and isoquinoline alkaloid biosynthesis. These changes in metabolic pathways may contribute to the tolerance and adaptability of S. fusiforme to high-temperature stress.

Highlights

Sargassum fusiforme is a fleshy, juicy, and flavoured marine vegetable with high nutritional and medicinal value (Schepetkin and Quinn 2006; Pugh and Pasco 2011)
By 7 days of heat stress, chlorophyll a content declined by 29% in the control plants, whereas that for 27 °C and 32 °C treatments declined by 37% and 42%, respectively
A total of 31 metabolites were significantly changed in the leaves of S. fusiforme exposed to 27 °C heat stress compared with control; this treatment caused an increase in 5 metabolites and a decrease in 26 metabolites, 9 of which were organic acids, 8 were amino acids, 4 were sugars or sugar alcohols, and 10 were other metabolites (Table 2)

Summary

Introduction

Sargassum fusiforme is a fleshy, juicy, and flavoured marine vegetable with high nutritional and medicinal value (Schepetkin and Quinn 2006; Pugh and Pasco 2011). It is highly recommended as a healthy longevity food, and is a warm temperate subtropical seaweed that mainly grows in the Northwest Pacific. It is found in the east of China (from the south of the Liaodong Peninsula to the Leizhou Peninsula in Guangdong), Japan (south of Hokkaido, from state to Kyushu), and the coast of Korea (Zhang et al 2002). S. fusiforme is largely produced in high quality in the Dongtou islands of Zhejiang costal area (Zeng 2000).

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