Heat Stress Targeting Individual Organs Reveals the Central Role of Roots and Crowns in Rice Stress Responses

• Published in: Frontiers in plant science 2022-01, Vol.12, p.799249-799249
• Main Authors: Prerostova, Sylva, Jarosova, Jana, Dobrev, Petre I, Hluskova, Lucia, Motyka, Vaclav, Filepova, Roberta, Knirsch, Vojtech, Gaudinova, Alena, Kieber, Joseph, Vankova, Radomira
• Format: Article
• Language: English
• Subjects: acclimation; antioxidant enzymes; cytokinin oxidase/dehydrogenase (CKX); gene expression; heat shock; jasmonoyl-isoleucine; Plant Science
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2021.799249

Inter-organ communication and the heat stress (HS; 45°C, 6 h) responses of organs exposed and not directly exposed to HS were evaluated in rice ( ) by comparing the impact of HS applied either to whole plants, or only to shoots or roots. Whole-plant HS reduced photosynthetic activity (F /F and QY ), but this effect was alleviated by prior acclimation (37°C, 2 h). Dynamics of , , , and expression revealed high protection of crowns and roots. Additionally, was strongly expressed in leaves. Whole-plant HS increased levels of jasmonic acid (JA) and cytokinin -zeatin in leaves, while up-regulating auxin indole-3-acetic acid and down-regulating -zeatin in leaves and crowns. Ascorbate peroxidase activity and expression of alternative oxidases ( ) increased in leaves and crowns. HS targeted to leaves elevated levels of JA in roots, -zeatin in crowns, and ascorbate peroxidase activity in crowns and roots. HS targeted to roots increased levels of abscisic acid and auxin in leaves and crowns, -zeatin in leaves, and JA in crowns, while reducing -zeatin levels. The weaker protection of leaves reflects the growth strategy of rice. HS treatment of individual organs induced changes in phytohormone levels and antioxidant enzyme activity in non-exposed organs, in order to enhance plant stress tolerance.