Synergistic Effects of a Night Temperature Shift and Methyl Jasmonate on the Production of Anthocyanin in Red Leaf Lettuce

Masaru Sakamoto,Takahiro Suzuki

doi:10.4236/ajps.2017.87106

Abstract

The production of a secondary metabolite such as anthocyanin is coordinately regulated by plant intrinsic factors and influenced by multiple environmental factors. In red leaf lettuce, the red pigment component anthocyanin is important for the commercial value of the crop, but its synchronous regulation by multiple factors is not well understood. Here, we examined the synergistic effects of a night temperature shift and methyl jasmonate (MJ) on the production of anthocyanin in red leaf lettuce. Low or high night temperature treatment for 3 days just before harvesting induced the production of anthocyanin without affecting plant biomass. Temperature-dependent activation of anthocyanin accumulation was accelerated by treating with MJ. Night temperature shifts and MJ triggered oxidative stresses in leaves, as indicated by hydrogen peroxide accumulation and lipid peroxidation. Interestingly, these oxidative stresses were more evident in leaves simultaneously treated with both a high night temperature and MJ. The activity of the superoxide dismutase (SOD) was increased alongside the elevation of oxidative stress. Taken together, these results indicate that the combined treatment of a night temperature shift with MJ may accelerate anthocyanin production by increasing the levels of oxidative stress to the leaves of red leaf lettuce.

Highlights

We examined the synergistic effects of a night temperature shift and methyl jasmonate (MJ) on the production of anthocyanin in red leaf lettuce
The activity of the superoxide dismutase (SOD) was increased alongside the elevation of oxidative stress. These results indicate that the combined treatment of a night temperature shift with MJ may accelerate anthocyanin production by increasing the levels of oxidative stress to the leaves of red leaf lettuce
In agreement with this result, the production of anthocyanin in second true leaves was significantly increased by the treatment of low night temperatures as compared with the control plants grown at 20 ̊C (Figure 3(A))

Summary

Introduction

A high or low temperature will often increase the production of secondary metabolites [3] [4] [5]. For example, induced leaf senescence and increased the secondary metabolite concentrations in the root of the herb Panax quinquefolius [6]. Spinach plants grown at a low temperature increased their production of sugar and ascorbic acid in leaves compared with those grown under ambient conditions [7]. The amount of ascorbic acid in the fruits increased when these plants were exposed to low temperature [8], whereas anthocyanin decreased at a high temperature [9]. Controlling the cultivation temperature may be an effective strategy for producing value-added crops that contain high amounts of useful secondary metabolites for humans

Methods

Results

Discussion

Conclusion