Fecha/hora: 16/06/2024 10:26:00

Biblioteca(s): 	INIA La Estanzuela.	
Fecha corriente: 	25/09/2020	
Fecha de la última actualización: 	12/08/2021	
Autoria: 	VANDEGEER, R.K.; ZHAO, C.; CIBILS-STEWART, X.; WUHRER, R.; HALL, C.R.; HARTLEY, S.E.; TISSUE, D.T.; JOHNSON, S.N.	
Afiliación: 	REBECCA K. VANDEGEERA, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia.; CHENCHEN ZHAO, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia.; XIMENA CIBILS-STEWART, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; RICHARD WUHRER, Advanced Materials Characterisation Facility (AMCF), Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia.; CASEY R. HALL, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia.; SUSAN E. HARTLEY, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK.; DAVID T. TISSUE, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia.; SCOTT N. JOHNSON, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia.	
Título: 	Silicon deposition on guard cells increases stomatal sensitivity as mediated by K+ efflux and consequently reduces stomatal conductance.	
Año de publicación: 	2021	
Fuente/Imprenta: 	Physiologia Plantarum, Volume 171, Issue 3, Pages 358-370,  March 2021. Doi: https://doi.org/10.1111/ppl.13202	
DOI: 	doi.org/10.1111/ppl.13202	
Idioma: 	Inglés	
Notas: 	Article history: First published: 03 September 2020/Version of Record online:16 September 2020/Accepted manuscript online:
03 September 2020/Manuscript accepted:01 September 2020/Manuscript revised:27 August 2020/Manuscript received:30 June 2020/First published: 03 September 2020.  Corresponding author: e-mail: R.Vandegeer@westernsydney.edu.au	
Contenido: 	Abstract: Silicon (Si) has been widely reported to improve plant resistance to water stress via various mechanisms including cuticular Si deposition to reduce leaf transpiration. However, there is limited understanding of the effects of Si on stomatal physiology, including the underlying mechanisms and implications for resistance to water stress. We grew tall fescue (Festuca arundinacea Schreb. cv. Fortuna) hydroponically, with or without Si, and treated half of the plants with 20% polyethylene glycol (PEG) to impose physiological drought (osmotic stress). Scanning electron microscopy (SEM) in conjunction with X-ray mapping (XRM) found that Si was deposited on stomatal guard cells and as a sub-cuticular layer in Si-treated plants. Plants grown in Si had a 28% reduction in stomatal conductance and a 23% reduction in cuticular conductance. When abscisic acid was applied exogenously to epidermal leaf peels to promote stomatal closure, Si plants had 19% lower stomatal aperture compared to control plants (i.e.increased stomatal sensitivity) and an increased efflux of guard cell K+ ions. However, the changes in stomatal physiology with Si were not substantial enough to improve water stress resistance, as shown by a lack of significant effect of Si on water potential, growth, photosynthesis and water-use efficiency.
Our findings suggest a novel underlying mechanism for reduced stomatal conductance with Si application; specifically, that Si deposition on stomatal guard cells promotes greater stomatal sensitivity as mediated by guard cell K+ efflux.	
Palabras-Clave: 	LEAF WATER POTENTIAL; PHOTOSYNTHESIS; RELATIVE WATER CONTENT; SCANNNG ELECTON MICROSCOPY.	
Thesagro: 	FESTUCA ARUNDINACEA.	
Categoría del tema: 	H01 Protección de plantas - Aspectos generales	
Registro original: 	INIA La Estanzuela (LE)	
Ejemplares: 	LE - (103200-1) - PXI - AP - DD - PP/Physiologia Plantarum/2021 -  -  - DIS