Wang Xiao-Dong, Zhang Yi-Nan, Wang Xiao-Guo, Zhuang Ye, Ge Shao-Hua
College of Agriculture, Henan University of Science and Technology, Luoyang, Henan, China.
Production Technology Section, Henan Province Tobacco Company, Jiyuan, Henan, China.
Front Plant Sci. 2025 Jan 20;15:1473565. doi: 10.3389/fpls.2024.1473565. eCollection 2024.
Drought stress severely affects global crop yields, reduces water availability, and hinders growth. Strigolactones can alleviate damage caused by various abiotic stresses in plants; however, limited research has been conducted on their ability to enhance drought tolerance in tobacco.
This study evaluated the drought tolerance of 'Qin Tobacco 96' (drought-tolerant) and 'Yun Tobacco 116' (moisture-sensitive) before and after the application of gibberellic acid lactone at a concentration of 0.2 mg·L⁻¹ under three drought conditions: mild, moderate, and severe. The primary drought tolerance traits were identified from 29 related indicators, including agronomic traits, photosynthetic efficiency, reactive oxygen metabolism, antioxidant enzyme activities, osmotic regulators, and hormone regulation, using affiliation function, principal component analysis, and cluster analysis to categorize the traits. The degree of drought tolerance enhancement in the two tobacco varieties was evaluated under various treatments.
Spraying exogenous strigolactones reduced the adverse effects of drought stress, particularly in the moisture-sensitive Y116 variety. Under drought stress, chlorophyll content and photosynthetic parameters significantly decreased, whereas strigolactone treatment increased both chlorophyll content and photosynthetic efficiency. Strigolactones reduced the accumulation of reactive oxygen species and malondialdehyde content, enhancing the antioxidant capacity of both varieties. Additionally, strigolactones increased the levels of osmoregulatory substances and activated the production of antioxidant enzymes, thereby enhancing drought tolerance. Furthermore, drought stress disrupted the balance of endogenous hormones, decreasing levels of auxin, gibberellic acid, and ribosylzeatin, while increasing abscisic acid levels. Exogenous strigolactones restored this hormonal balance.
Sixteen traits associated with drought tolerance in tobacco were analyzed using principal component analysis, the traits were classified using cluster analysis, and the magnitude of the D-value was determined by calculating the values of the affiliation function and their respective weights. The results indicated that a concentration of 0.2 mg·L⁻¹ of strigolactones enhanced the drought tolerance of tobacco across different levels of drought stress and promoted the growth and development of flue-cured tobacco. However, the interactions between strigolactones and various hormones under drought stress require further investigation to elucidate the underlying molecular mechanisms. The application methods of strigolactones should be optimized.
干旱胁迫严重影响全球作物产量，降低水分可利用性，并阻碍生长。独脚金内酯可以减轻植物中各种非生物胁迫造成的损害；然而，关于其增强烟草耐旱性能力的研究有限。
本研究评估了在轻度、中度和重度三种干旱条件下，施用浓度为0.2 mg·L⁻¹的赤霉素内酯前后，‘秦烟96’（耐旱型）和‘云烟116’（水分敏感型）的耐旱性。从29个相关指标中确定主要耐旱性状，包括农艺性状、光合效率、活性氧代谢、抗氧化酶活性、渗透调节物质和激素调节，使用隶属函数、主成分分析和聚类分析对这些性状进行分类。评估了两个烟草品种在不同处理下耐旱性增强的程度。
喷施外源独脚金内酯减轻了干旱胁迫的不利影响，尤其是在水分敏感型Y116品种中。在干旱胁迫下，叶绿素含量和光合参数显著降低，而独脚金内酯处理增加了叶绿素含量和光合效率。独脚金内酯减少了活性氧的积累和丙二醛含量，增强了两个品种的抗氧化能力。此外，独脚金内酯增加了渗透调节物质的水平并激活了抗氧化酶的产生，从而增强了耐旱性。此外，干旱胁迫破坏了内源激素的平衡，降低了生长素、赤霉素和核糖基玉米素的水平，同时增加了脱落酸水平。外源独脚金内酯恢复了这种激素平衡。
通过主成分分析对与烟草耐旱性相关的16个性状进行了分析，通过聚类分析对性状进行了分类，并通过计算隶属函数值及其各自权重确定了D值的大小。结果表明，浓度为0.2 mg·L⁻¹的独脚金内酯增强了烟草在不同干旱胁迫水平下的耐旱性，并促进了烤烟的生长发育。然而，干旱胁迫下独脚金内酯与各种激素之间的相互作用需要进一步研究以阐明潜在的分子机制。应优化独脚金内酯的施用方法。
