Influence of vesicular trichomes of Atriplex nummularia on photosynthesis, osmotic adjustment, cell wall elasticity and enzymatic activity

• Published in: Plant physiology and biochemistry Vol. 155; pp. 177 - 186
• Main Authors: Paulino, Martha Katharinne Silva Souza, Souza, Edivan Rodrigues de, Lins, Cíntia Maria Teixeira, Dourado, Pablo Rugero Magalhães, Leal, Lucas Yago de Carvalho, Monteiro, Danilo Rodrigues, Rego Junior, Francisco Ernesto de Andrade, Silva, Cláudia Ulisses de Carvalho
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.10.2020
• Subjects: Antioxidant enzymes; Antioxidants - physiology; Atriplex - enzymology; Atriplex - physiology; Cell Wall - physiology; Elasticity; Gas exchange; Halophyte; Hydrogen Peroxide; Osmotic Pressure; Photosynthesis; Plant Leaves; Pressure-volume curve; Reactive Oxygen Species; Salt stress; Salt-Tolerant Plants - physiology; Trichomes - physiology; Water relations; Halophyte; Salt stress; Gas exchange; Antioxidant enzymes; Pressure-volume curve; Water relations
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2020.07.036

Vesicular trichomes play a key role in excluding toxic ions from some halophyte species, preventing the essential processes and functions of plants from being altered. Thus, the present study aimed to evaluate the influence of these structures on Atriplex nummularia irrigated using waters with three levels of osmotic potential (−0.1, −1.4 and −2.7 MPa), formulated with NaCl in plants with vesicular trichomes and plants with partial removal of trichomes. The experiment was conducted in a protected environment and plants were evaluated for physiological parameters (water, osmotic and pressure potentials, relative water content, osmotic adjustment, pressure-volume curve, gas exchange), electrolyte leakage, lipid peroxidation and enzymatic activity (superoxide dismutase, ascorbate peroxidase, catalase). The results obtained made it possible to identify the strong contribution of vesicular trichomes to physiological and biochemical parameters, with indication of cell wall stiffening and maintenance of turgor. Furthermore, the evaluation of the osmotic potentials obtained in the study suggests that the contribution of vesicular trichomes to the salinity tolerance of the species is greater than that of osmotic adjustment. Furthermore, gas exchange results suggest that the presence of trichomes was able to regulate stomatal processes so that the plant maintains its photosynthetic performance. Evaluation of electrolyte leakage, together with the increase in malondialdehyde content, showed that the maintenance of trichomes reduces the probability of oxidative stress. The activity of antioxidant enzymes was efficient in eliminating reactive oxygen species, especially the activity of ascorbate peroxidase, which stood out in terms of hydrogen peroxide detoxification. •Vesicular trichomes play a key role in excluding toxic ions.•Irrigation with saline water contributes to cell wall rigidity.•Maintenance of trichomes helps maintain photosynthetic efficiency.•Presence of trichomes reduces the occurrence of oxidative stress.