Control of leaf growth by abscisic acid: hydraulic or non‐hydraulic processes?

摘要: Abscisic acid (ABA) affects plant metabolism and water transfers via multiple mechanisms at cell, organ whole levels. These translate into contradictory effects on leaf growth, so the literature reports positive, null or negative of ABA growth upon deficit. We review evidences based genetic manipulations biosynthesis, feeding with artificial partial root drying provide elements to avoid confusions effects. propose that has mainly three growth. (i) Via its controlling effect stomatal aperture transpiration rate, an increased concentration tends buffer day-night alternations rate evaporative demand. (ii) improve increase in conductance transfer as a result tissue hydraulic conductivity. (iii) also modest non-hydraulic which is plants subjected deficit, either manipulated for synthesis fed ABA, but can be positive well watered deficient ABA. The overall increasing biosynthesis depends relative weight each these under different environmental scenarios.