Stomatal malfunctioning under low VPD conditions: induced by alterations in stomatal morphology and leaf anatomy or in the ABA signaling?
Article first published online: 10 JUN 2014
© 2014 Scandinavian Plant Physiology Society
Volume 152, Issue 4, pages 688–699, December 2014
How to Cite
Aliniaeifard, S., Malcolm Matamoros, P. and van Meeteren, U. (2014), Stomatal malfunctioning under low VPD conditions: induced by alterations in stomatal morphology and leaf anatomy or in the ABA signaling?. Physiologia Plantarum, 152: 688–699. doi: 10.1111/ppl.12216
- Issue published online: 20 NOV 2014
- Article first published online: 10 JUN 2014
- Accepted manuscript online: 28 APR 2014 12:33PM EST
- Manuscript Accepted: 21 MAR 2014
- Manuscript Revised: 12 MAR 2014
- Manuscript Received: 3 FEB 2014
- Ministry of Science, Research and Technology of Iran. Grant Number: 24/88100010
Exposing plants to low VPD reduces leaf capacity to maintain adequate water status thereafter. To find the impact of VPD on functioning of stomata, stomatal morphology and leaf anatomy, fava bean plants were grown at low (L, 0.23 kPa) or moderate (M, 1.17 kPa) VPDs and some plants that developed their leaves at moderate VPD were then transferred for 4 days to low VPD (ML). Part of the ML-plants were sprayed with ABA (abscisic acid) during exposure to L. L-plants showed bigger stomata, larger pore area, thinner leaves and less spongy cells compared with M-plants. Stomatal morphology (except aperture) and leaf anatomy of the ML-plants were almost similar to the M-plants, while their transpiration rate and stomatal conductance were identical to that of L-plants. The stomatal response to ABA was lost in L-plants, but also after 1-day exposure of M-plants to low VPD. The level of foliar ABA sharply decreased within 1-day exposure to L, while the level of ABA-GE (ABA-glucose ester) was not affected. Spraying ABA during the exposure to L prevented loss of stomatal closing response thereafter. The effect of low VPD was largely depending on exposure time: the stomatal responsiveness to ABA was lost after 1-day exposure to low VPD, while the responsiveness to desiccation was gradually lost during 4-day exposure to low VPD. Leaf anatomical and stomatal morphological alterations due to low VPD were not the main cause of loss of stomatal closure response to closing stimuli.