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Publication Type J
Authors Lu, X. P., H. J. Gao, L. Zhang, Y. P. Wang, K. Z. Shao, Q. Zhao and J. L. Zhang
Title Dynamic responses of Haloxylon ammodendron to various degrees of simulated drought stress
Source Plant Physiology and Biochemistry
Author Keywords Haloxylon ammodendron Simulated drought stress Osmotic regulators Na+ Antioxidase water-deficit tolerance osmotic adjustment abiotic stress sodium-chloride salt-tolerance physiological adjustment proline accumulation potassium-transport antioxidant enzymes k+/na+ homeostasis
Abstract Haloxylon ammodendron, a C4 perennial, succulent and xero-halophytic shrub, is highly resistant to harsh environments, therefore, exploring the stress resistance mechanism will be beneficial for the use of xerophytes to prevent desertification. To determine osmotic adjustment (OA) and antioxidase functions under simulated drought stress, 8-week-old seedlings were treated with sorbitol solutions to maintain osmotic potentials (Psi s) at a control and -0.5 and -1.0 MPa. Under -0.5 MPa osmotic stress, H. ammodendron stably maintained the water content of assimilating branches, a result that was not significantly different from the result of the control group. Moreover, the Psi s decreased significantly, which helped plants absorb water efficiently from the environment, as H. ammodendron accumulated massive osmotic regulators in its assimilating branches to adjust shoot Psi s. Specifically, the contribution of Na+ to shoot Psi s was up to 45%, and Na+ became the main osmotic regulator of OA. During the treatments, the content and contribution of K+ remained stable. However, the total contribution of three organic osmotic regulators (free proline, betaine and soluble sugar) was only 20%, and betaine was the main organic osmotic regulator, accounting for approximately 15% of the 20% contribution. Moreover, H. ammodendron seedlings presented strong antioxidases, especially when there was a high activity level of superoxide dismutase, and with an increase in treatment time and degree of osmotic stress, the activity of peroxidase and catalase increased significantly. Substantial accumulation of osmotic adjustment substances was an important strategy for H. ammodendron to cope with simulated drought stress, in particular, H. ammodendron absorbed much Na+ and transported Na+ into the assimilating branch for OA. The scavenging of reactive oxygen species by antioxidases was another adaptation strategy for H. ammodendron to adapt to simulated drought stress.
Author Address [Zhang, Jin-Lin] Lanzhou Univ, State Key Lab Grassland Agroecosyst, Lanzhou 730000, Gansu, Peoples R China. Lanzhou Univ, Minist Agr & Rural Affairs, Key Lab Grassland Livestock Ind Innovat, Lanzhou 730000, Gansu, Peoples R China. Lanzhou Univ, Minist Educ, Engn Res Ctr Grassland Ind, Lanzhou 730000, Gansu, Peoples R China. Lanzhou Univ, Coll Pastoral Agr Sci & Technol, Lanzhou 730000, Gansu, Peoples R China. Zhang, JL (reprint author), Lanzhou Univ, State Key Lab Grassland Agroecosyst, Lanzhou 730000, Gansu, Peoples R China. jlzhang@lzu.edu.cn
ISSN 0981-9428
ISBN 0981-9428
29-Character Source Abbreviation Plant Physiol. Biochem.
Publication Date Jun
Year Published 2019
Volume 139
Beginning Page 121-131
Digital Object Identifier (DOI) 10.1016/j.plaphy.2019.03.019
Unique Article Identifier WOS:000469896200012
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