Yang Jingli, Song Jinnan, Liu Jie, Dong Xinxiu, Zhang Haijun, Jeong Byoung Ryong
Weifang Key Laboratory for Stress Resistance and High Yield Regulation of Horticultural Crops, Shandong Provincial University Laboratory for Protected Horticulture, College of Jia Sixie Agriculture, Weifang University of Science and Technology, Shouguang 262700, China.
Department of Horticulture, Division of Applied Life Science (BK21 Four), Graduate School, Gyeongsang National University, Jinju 52828, Republic of Korea.
Plants (Basel). 2024 Sep 12;13(18):2564. doi: 10.3390/plants13182564.
To investigate the relationship between the lighting direction-induced morphophysiological traits and post-harvest storage of lettuce, the effects of different lighting directions (top, T; top + side, TS; top + bottom, TB; side + bottom, SB; and top + side + bottom, TSB; the light from different directions for a sum of light intensity of 600 μmol·m·s photosynthetic photon flux density (PPFD)) on the growth morphology, root development, leaf thickness, stomatal density, chlorophyll concentration, photosynthesis, and chlorophyll fluorescence, as well as the content of nutrition such as carbohydrates and soluble proteins in lettuce were analyzed. Subsequently, the changes in water loss rate, membrane permeability (measured as relative conductivity and malondialdehyde (MDA) content), brittleness (assessed by both brittleness index and β-galactosidase (β-GAL) activity), and yellowing degree (evaluated based on chlorophyll content, and activities of chlorophyllase (CLH) and pheophytinase (PPH)) were investigated during the storage after harvest. The findings indicate that the TS treatment can effectively reduce shoot height, increase crown width, enhance leaves' length, width, number, and thickness, and improve chlorophyll fluorescence characteristics, photosynthetic capacity, and nutrient content in lettuce before harvest. Specifically, lettuce's leaf thickness and stomatal density showed a significant increase. Reasonable regulation of water loss in post-harvested lettuce is essential for delaying chlorophyll degradation. It was utilized to mitigate the increase in conductivity and hinder the accumulation of MDA in lettuce. The softening speed of leafy vegetables was delayed by effectively regulating the activity of the β-GAL. Chlorophyll degradation was alleviated by affecting CLH and PPH activities. This provides a theoretical basis for investigating the relationship between creating a favorable light environment and enhancing the post-harvest preservation of leafy vegetables, thus prolonging their post-harvest storage period through optimization of their morphophysiological phenotypes.
为研究光照方向诱导的形态生理特性与生菜采后贮藏之间的关系，分析了不同光照方向（顶部，T；顶部+侧面，TS；顶部+底部，TB；侧面+底部，SB；以及顶部+侧面+底部，TSB；来自不同方向的光，光合光子通量密度（PPFD）总和为600 μmol·m·s）对生菜生长形态、根系发育、叶片厚度、气孔密度、叶绿素浓度、光合作用、叶绿素荧光以及碳水化合物和可溶性蛋白质等营养成分含量的影响。随后，研究了收获后贮藏期间生菜的失水率、膜通透性（以相对电导率和丙二醛（MDA）含量衡量）、脆性（通过脆性指数和β-半乳糖苷酶（β-GAL）活性评估）以及黄化程度（基于叶绿素含量、叶绿素酶（CLH）和脱镁叶绿素酶（PPH）活性评估）的变化。研究结果表明，TS处理可有效降低生菜株高，增加冠幅，增大叶片长度、宽度、数量和厚度，并改善收获前生菜的叶绿素荧光特性、光合能力和营养成分含量。具体而言，生菜叶片厚度和气孔密度显著增加。合理调控采后生菜的水分流失对于延缓叶绿素降解至关重要。这有助于减轻生菜电导率的增加并抑制MDA的积累。通过有效调节β-GAL的活性可延缓叶菜类蔬菜的软化速度。通过影响CLH和PPH的活性可减轻叶绿素降解。这为研究营造良好光照环境与增强叶菜类蔬菜采后保鲜之间的关系提供了理论依据，从而通过优化其形态生理表型延长其采后贮藏期。
