The Positive Effects of Increased Light Intensity on Growth and Photosynthetic Performance of Tomato Seedlings in Relation to Night Temperature Level

Jiaohong Song,Mohammad Shah Jahan,Yixuan Wen,Xiaoying Liu,Aoxue Zhang,Mengli Wang,Zheng Chen

doi:10.3390/agronomy12020343

Abstract

Light and temperature are related to the growth and development of plants as well as their energy consumption in plant factories. However, most of the studies to date have focused on light and temperature extremes, while the adaptive responses and underlying mechanisms of plants to non-stress light intensity (LI) and night temperature (NT) largely remain elusive. Here, we investigated the growth and physiological responses of tomatoes grown under three LI regimes of 250 (LL), 300 (LM), and 350 (LH) μmol m−2 s−1, respectively, combined with two NT conditions. The results revealed that increased LI comprehensively improved tomato growth and physiological status at lower NT levels, but the growth stimulations induced by increasing LI were limited by higher NT. In addition, the lower NT at LM and LH conferred a relatively better endogenous physiological condition and significantly promoted tomato growth, but the higher NT significantly accelerated shoot growth at LL, indicating a compensation of higher NT for low light induced growth restriction. Taken together, the current study suggests that the adaptation mechanism of tomato plants to higher NT varied with LI levels, and higher LI plus lower NT would be an effective strategy to improve tomato growth.

Highlights

Plant factories can avoid unfavorable external environmental factors during crop production, so growing and nourishing vegetables is very stable throughout the year, letting an uninterrupted supply of vegetables at a constant price, regardless of weather conditions.in an artificially controlled plant factory, one of the biggest challenges is the massive energy consumption due to the maintenance and regulation of light and temperature environments [1]
F-test indicated that light intensity (LI) and night temperature (NT) as well as their interaction significantly affected tomato seedling growth (Figures 1 and 2A–E)
The present study showed that continuously increased LI, especially at lower NT level, comprehensively improved plants growth quality and physiological traits (Figures 1, 2, 5 and 6, Table 1), which is consistent with the previous results that increased LI allows better performances of Chinese red radish and rape seedlings [26,27]

Summary

Introduction

Plant factories can avoid unfavorable external environmental factors during crop production, so growing and nourishing vegetables is very stable throughout the year, letting an uninterrupted supply of vegetables at a constant price, regardless of weather conditions.in an artificially controlled plant factory, one of the biggest challenges is the massive energy consumption due to the maintenance and regulation of light and temperature environments [1]. Light and temperature are the two most crucial environmental stimuli that regulated plant growth and development [2], and serve as cues to initiate multiple developmental processes, but are required for optimal performances of biochemical and physiological cascades in the normal plant life cycle [3]. Understanding the responses in the growth and development of the plants to different light and temperature levels is an essential prerequisite for deciphering appropriate strategies to regulate environmental parameters in plant factories. Plants have evolved a wide range of growth and survival mechanisms, including plant morphological and physiological changes, to adapt to light and temperature environments [1,2,4,5]. Plants have evolved multiple receptors to perceive new environmental signals and changes in environmental conditions as well, and transform the information into downstream metabolic or biochemical changes to facilitate plants to survive under given LI conditions [2]

Methods

Results

Discussion

Conclusion