Pre-drought priming sustains grain development under post-anthesis drought stress by regulating the growth hormones in winter wheat (Triticum aestivum L.)

• Published in: Planta Vol. 246; no. 3; pp. 509 - 524
• Main Authors: Abid, Muhammad, Shao, Yuhang, Liu, Sixi, Wang, Feng, Gao, Jingwen, Jiang, Dong, Tian, Zhongwei, Dai, Tingbo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Science + Business Media 01.09.2017; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Abscisic acid; Acetic acid; Agriculture; Biomedical and Life Sciences; Cell Division; Chlorophyll; Chlorophyll - analysis; Damage; Dehydration; Drought; Droughts; Ecology; Endosperm; Endosperm - cytology; Forestry; Gibberellins; Grain size; Growth hormones; Hormones; Indoleacetic acid; Life Sciences; ORIGINAL ARTICLE; Photosynthesis; Plant growth; Plant Growth Regulators - physiology; Plant Leaves - chemistry; Plant Leaves - physiology; Plant Sciences; Priming; Seeds - growth & development; Stresses; Triticum - growth & development; Triticum - physiology; Triticum aestivum; Water - metabolism; Water potential; Wheat; Winter wheat; Zeatin; Zeatin riboside; Grain development; ); Post-anthesis drought stress; Plant growth hormones; Pre-drought priming; Winter wheat; Winter wheat (Triticum aestivum)
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-017-2698-4

Post-anthesis drought stress substantially reduces grain yield in wheat (Triticum aestivum L.) due to impaired grain development associated with imbalanced levels of growth hormones. To investigate whether pre-drought priming could sustain grain development in wheat by regulating favorable levels of growth hormones under post-anthesis drought conditions, the plants of a drought-sensitive (Yangmai-16) and drought-tolerant (Luhan-7) wheat cultivar were exposed to a moderate drought stress during tillering (Feekes 2 stage) for priming, and then, a subsequent severe drought stress was applied from 7 to 14 days after anthesis. The results showed that drought-stressed plants of both cultivars showed a decline in flag leaf water potential, chlorophyll contents, photosynthetic rate, grain size initiation, and grain filling as compared to well-watered plants; however, decline in these traits was less in pre-drought primed (PD) plants than in nonprimed (ND) plants. Under drought stress, the PD plants regulated higher concentrations of zeatin and zeatin riboside, indole-3-acetic acid, gibberellins, and lower abscisic acid content in grains, resulting in higher endosperm cell division and expansion, grain size initiation, grain-filling rate and duration, and finally higher grain dry weights as compared to ND plants. The PD plants of both cultivars showed higher potential to tolerate the post-anthesis drought stress, but more effect was displayed by drought-tolerant cultivar. From the achieved results, it was concluded that predrought priming facilitated the wheat plants to sustain higher grain development and yield against the most yield-damaging post-anthesis drought stress by modulating the levels of growth hormones.