Effects of Water Stress on Carbon Exchange Rate and Activities of Photosynthetic Enzymes in Leaves of Sugarcane ( Saccharum Sp.)

Citations Over TimeTop 10% of 1996 papers

Abstract

The responses of carbon exchange rate (CER), stomatal conductance (gs), activities of phosphoenolpyruvate carboxylase (PEPcase), NADP malic enzyme (NADP-ME), ribulose-1,5- bisphosphate carboxylase (Rubisco), fructose-1,6-bisphosphatase (FBPase) and pyruvate, orthophosphate dikinase (PPDK), and contents of chlorophyll (Chl) and total soluble protein (Tsp) in leaves of sugar cane (Saccharum sp. cv. NiF4) to gradually developed water stress were investigated. The initial inhibitions of CER, gs, activities of the photosynthetic enzymes and contents of Chl and Tsp were observed from leaf water potentials (Ψw) of -0.37 MPa. During water stress, CER and gs, decreased in a non-linear way, activities of the five enzymes and contents of Chl and Tsp decreased linearly with decreasing leaf Ψw. The changes of gs the photosynthetic enzymes, Chl and Tsp were highly related to the changes of CER. The decline in CER during water stress was caused by both stomatal and non- stomatal limitations. Above leaf ¨w of -0.85 MPa, the decline in CER was caused by stomatal closure, below -0.85 MPa, the decline in CER was caused by non-stornatal limitation. Among non-stomatal components, PPDK activities decreased 9.1 times during water stress, much more than other enzymes which decreased from 2 to 4 times. Measured PPDK activities were only a little higher than the corresponding CER values at various leaf Ψw suggesting that PPDK is very likely to be the limiting enzyme to photosynthesis under water stress.

Related Papers

• → Increasing the Acetyl-CoA Pool in the Presence of Overexpressed Phosphoenolpyruvate Carboxylase or Pyruvate Carboxylase Enhances Succinate Production in Escherichia coli(2004)78 cited
• → Development of C4 photosynthesis in sorghum leaves grown under free-air CO2 enrichment (FACE)(2003)42 cited
• → Ribulose-1,5-bisphosphate carboxylase and phosphoenolpyruvate carboxylase activities of photoautotrophic callus of Platycerium coronarium (Koenig ex O.F. Muell.) Desv. under CO2 enrichment(1997)7 cited
• → Did early land plants use carbon-concentrating mechanisms?(2012)3 cited
• → Pyruvate carboxylase and phosphoenolpyruvate carboxykinase in cultured human fibroblasts(1977)23 cited