Abstract:
The extent of drought tolerance in the seedlings of three wheat cultivars (WMRI-1, BARI GOM-33 and BARI GOM-21) was investigated by seed and root priming using abscisic acid (ABA) and glycine betaine (GB). The seeds were primed with ABA (10 and 20 μM) and GB (50 and 100 mM) and grown in pots maintaining control (0 % PEG) and drought (10 % PEG) conditions. Under drought, the root and shoot length, root and shoot biomass were significantly increased in ABA and GB primed seedlings than non-primed seedlings in all cultivars. Among the priming agents, either 20 μM ABA or 50 mM GB triggered better seedling growth in all wheat cultivars. These two levels were then applied with the nutrient solution in the hydroponics following four treatments: Control, Drought, Drought + ABA and Drought + GB. The seedling growth significantly declined in drought, while an improved seedling growth was observed in ABA and GB-treated plants in all cultivars. A considerable increase in lipid peroxidation, proline content, total antioxidant capacity and total flavonoid content in roots and leaves were recorded in all drought conditions, while these values were considerably reduced in ABA and GB treatments. Hierarchical clustering heatmap using stress tolerance index (STI) values showed that Drought + ABA and Drought + GB secured higher STI scores suggesting a greater degree of drought tolerance in all cultivars. In conclusion, seed and root priming of ABA and GB enhanced drought tolerance in the wheat seedlings by improving seedling growth and antioxidative defense suggesting a declined state of oxidative damage.
摘要:
通过使用脱落酸(ABA)和甘氨酸甜菜碱(GB)进行种子和根引发,研究了三个小麦品种(WMRI-1,BARIGOM-33和BARIGOM-21)幼苗的耐旱性。用ABA(10和20μM)和GB(50和100mM)引发种子,并在保持对照(0%PEG)和干旱(10%PEG)条件的盆中生长。在干旱下,根和芽的长度,在所有品种中,ABA和GB引发的幼苗的根和芽生物量均比未引发的幼苗显着增加。在启动剂中,20μMABA或50mMGB可在所有小麦品种中引发更好的幼苗生长。然后在四个处理后,将这两个水平与营养液一起应用于水培中:对照,干旱,干旱+ABA和干旱+GB。干旱使幼苗生长明显下降,在所有品种的ABA和GB处理的植物中均观察到幼苗生长改善。脂质过氧化的显著增加,脯氨酸含量,在所有干旱条件下记录根和叶的总抗氧化能力和总黄酮含量,而这些值在ABA和GB处理中大大降低。使用胁迫耐受性指数(STI)值进行的分层聚类热图显示,干旱ABA和干旱GB获得了较高的STI分数,表明所有品种的耐旱性都更高。总之,ABA和GB的种子和根引发通过改善幼苗生长和抗氧化防御来增强小麦幼苗的耐旱性,表明氧化损伤状态下降。