Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Center of Nanfan and High-Efficiency Tropical Agriculture, Hainan University, Sanya, 572025, China.
Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Danzhou, 571737, China.
Plant Cell Rep. 2024 Mar 26;43(4):106. doi: 10.1007/s00299-024-03196-w.
Exogenous SL positively regulates pepper DS by altering the root morphology, photosynthetic character, antioxidant enzyme activity, stomatal behavior, and SL-related gene expression. Drought stress (DS) has always been a problem for the growth and development of crops, causing significant negative impacts on crop productivity. Strigolactone (SL) is a newly discovered class of plant hormones that are involved in plants' growth and development and environmental stresses. However, the role of SL in response to DS in pepper remains unknown. DS considerably hindered photosynthetic pigments content, damaged root architecture system, and altered antioxidant machinery. In contrast, SL application significantly restored pigment concentration modified root architecture system, and increased relative chlorophyll content (SPAD). Additionally, SL treatment reduced oxidative damage by reducing hydrogen peroxide (HO) (24-57%) and malondialdehyde (MDA) (79-89%) accumulation in pepper seedlings. SL-pretreated pepper seedlings showed significant improvement in antioxidant enzyme activity, proline accumulation, and soluble sugar content. Furthermore, SL-related genes (CcSMAX2, CcSMXL6, and CcSMXL3) were down-regulated under DS. These findings suggest that the foliar application of SL can alleviate the adverse effects of drought tolerance by up-regulating chlorophyll content and activating antioxidant defense mechanisms.
外源 SL 通过改变根系形态、光合特性、抗氧化酶活性、气孔行为和 SL 相关基因表达正向调控辣椒 DS。干旱胁迫（DS）一直是作物生长和发育的问题，对作物生产力造成重大负面影响。独脚金内酯（SL）是一类新发现的植物激素，参与植物的生长发育和环境胁迫。然而，SL 在应对辣椒 DS 中的作用尚不清楚。DS 极大地抑制了光合色素的含量，破坏了根系结构系统，并改变了抗氧化机制。相比之下，SL 的应用显著恢复了色素浓度，改变了根系结构系统，并增加了相对叶绿素含量（SPAD）。此外，SL 处理通过减少 H2O2（24-57%）和 MDA（79-89%）在辣椒幼苗中的积累，减轻了氧化损伤。用 SL 预处理的辣椒幼苗的抗氧化酶活性、脯氨酸积累和可溶性糖含量显著提高。此外，DS 下 SL 相关基因（CcSMAX2、CcSMXL6 和 CcSMXL3）下调。这些发现表明，叶片喷施 SL 可以通过提高叶绿素含量和激活抗氧化防御机制来缓解耐旱性的不良影响。
