Yao Luhua, Wu Yitao
Department of Agriculture and Forestry, Hainan Tropical Ocean University, Sanya, Hainan Province, China.
PeerJ. 2025 Sep 10;13:e20014. doi: 10.7717/peerj.20014. eCollection 2025.
Seed priming is an affordable and effective method to enhance crop drought tolerance by improving seed germination and seedling vigor. However, whether seed priming alters cuticle formation, which could contribute to drought resistance in seedlings, remains unclear.
In this study, sweet sorghum seeds belonging to three varieties were primed with salicylic acid (SA) and the seedlings were exposed to drought stress. The seeds were primed with SA with concentrations of 50, 100, 150, 200, 250 mg L. For drought treatment (35% field capacity, 80% of field capacity as the normal condition), both SA-primed and non-primed seeds were planted in a soil mixture.
Under drought conditions, SA priming at 150 mg L significantly increased total wax content (12.3%-33.3%), primary alcohol content (42.0%-57.0%), proline content (70.9%-119%), leaf water content (9.8%-36.6%), water use efficiency (28.4%-120%), and biomass (25%-30%). Additionally, leaf water loss rate and chlorophyll leaching rate were significantly reduced. Correlation analysis revealed strong positive associations ( = 0.79-0.86, < 0.001) between total wax content and water status as well as proline content. Furthermore, under both well-watered and drought conditions, SA priming at 150 mg L significantly increased leaf wax content and biomass in all sorghum varieties.
Seed priming with salicylic acid at 150 mg L not only promotes normal growth under well-watered conditions, but also enhances sorghum's adaptability to drought stress, ultimately contributing to drought tolerance without penalizing growth.
种子引发是一种经济有效的方法，可通过提高种子发芽率和幼苗活力来增强作物的耐旱性。然而，种子引发是否会改变角质层形成（这可能有助于幼苗的抗旱性）仍不清楚。
在本研究中，用三种水杨酸（SA）对三个品种的甜高粱种子进行引发处理，并使幼苗遭受干旱胁迫。用浓度为50、100、150、200、250mg/L的SA对种子进行引发处理。对于干旱处理（田间持水量的35%，正常条件为田间持水量的80%），将经过SA引发处理和未经过引发处理的种子都种植在混合土壤中。
在干旱条件下，150mg/L的SA引发处理显著提高了总蜡含量（12.3%-33.3%）、伯醇含量（42.0%-57.0%）、脯氨酸含量（70.9%-119%）、叶片含水量（9.8%-36.6%）、水分利用效率（28.4%-120%）和生物量（25%-30%）。此外，叶片失水率和叶绿素浸出率显著降低。相关性分析表明，总蜡含量与水分状况以及脯氨酸含量之间存在强正相关（r=0.79-0.86，P<0.001）。此外，在浇水良好和干旱条件下，150mg/L的SA引发处理均显著提高了所有高粱品种的叶片蜡含量和生物量。
150mg/L的水杨酸引发种子不仅能促进浇水良好条件下的正常生长，还能增强高粱对干旱胁迫的适应性，最终有助于提高耐旱性而不影响生长。
