The role of inorganic phosphate on photosynthesis recovery of common bean after a mild water deficit

• Published in: Plant science (Limerick) Vol. 170; no. 3; pp. 659 - 664
• Main Authors: dos Santos, Mauro Guida, Ribeiro, Rafael Vasconcelos, de Oliveira, Ricardo Ferraz, Machado, Eduardo Caruso, Pimentel, Carlos
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.03.2006; Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; assimilation (physiology); beans; Biological and medical sciences; carbon dioxide; chlorophyll; Chlorophyll fluorescence; Drought; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Gas exchange; inorganic phosphate; leaf water potential; Oxygen evolution; Phaseolus vulgaris; phosphates; photosynthesis; stomatal conductance; Water relations, transpiration, stomata; water stress; A; ETR; A c; PT; C i; NPQ; Chlorophyll fluorescence; Phaseolus vulgaris; Oxygen evolution; Pi; Ψ l; g s; PPFD; Gas exchange; Drought; Assimilation; Chlorophyll; Water deficit; Carbon dioxide; Stomatal conductance; Water stress; Pollination; Leguminosae; Dicotyledones; Angiospermae; Spermatophyta; Photosynthesis
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2005.10.020

A foliar spray of inorganic phosphate (Pi) was applied at the pollination stage of two common bean genotypes A320 and Ouro Negro, growing in pots in a greenhouse. Two days after the foliar Pi supply, a mild water deficit was imposed for 7 days and photosynthesis was evaluated during water stress and recovery. The net CO 2 assimilation rate ( A) and stomatal conductance ( g s) were not affected by Pi supply during the dehydration of either genotype. On the fourth day of water deficit, A320 presented a high value of A despite lower g s, indicating a small effect of g s on A for this genotype, while Ouro Negro showed a low value for both A and g s. However, after rehydration A and g s for A320 and A for Ouro Negro, both supplied with Pi, were higher than for non-Pi-supplied plants. In addition, the O 2 evolution ( A c) of rehydrated A320 with foliar Pi supply was also higher than for non-Pi-supplied plants, and the non-photochemical quenching (NPQ) was higher for rehydrated A320 without foliar Pi. The results revealed an up-regulation of the recovery of photosynthesis after water deficit induced by the foliar Pi supply, which was genotype-specific.