Changes in net photosynthetic rate and chlorophyll fluorescence in potato leaves induced by water stress

Net rates of photosynthesis (PN) saturated by irradiance of >500 μmol m-2 s-1 (PAR) significantly decreased in water-stressed potato (Solanum tuberosum L. cv. Kufri Sindhuri) plants. The quantum yield of photochemical energy conversion (Fv/Fm), relative electron transport rate (ETR), and photochemical quenching (Qp) exhibited a parallel decline at high irradiance. A slight decrease in relative water content (RWC) was accompanied by a drastic decline in leaf water potential (Ψw) from -0.2 to -1.0 MPa. Dehydrated leaves showed an increase in the amount of total soluble sugars per unit leaf area which inhibited the photosynthesis in a feedback manner. After rewatering, PN and Fv/Fm were restored to the values of control plants within 24 h, and the restoration was accompanied by a proportionate lowering of content of total soluble sugars in the leaves.

[1]  S. Huber,et al.  Regulation of photosynthesis by end-product accumulation in leaves of plants storing starch, sucrose, and hexose sugars. , 1992, Plant physiology.

[2]  J. Snel,et al.  The use of chlorophyll fluorescence nomenclature in plant stress physiology , 1990, Photosynthesis Research.

[3]  I. R. Cowan,et al.  Leaf Conductance in Relation to Rate of CO(2) Assimilation: III. Influences of Water Stress and Photoinhibition. , 1985, Plant physiology.

[4]  E. Handel.  Direct microdetermination of sucrose , 1968 .

[5]  W. Bilger,et al.  Continuous recording of photochemical and non-photochemical chlorophyll fluorescence quenching with a new type of modulation fluorometer , 2004, Photosynthesis Research.

[6]  A. Migge,et al.  THE ROLE OF MALATE DEHYDROGENASE IN DISSIPATING EXCESS ENERGY UNDER WATER STRESS IN TWO WHEAT SPECIES , 1996 .

[7]  J. Vos,et al.  Water Relations of Potato Leaves, I. Diurnal Changes, Gradients in the Canopy, and Effects of Leaf-insertion Number, Cultivar and Drought , 1988 .

[8]  M. Stitt,et al.  Control of Photosynthetic Sucrose Formation , 1987 .

[9]  Norton Nelson,et al.  A PHOTOMETRIC ADAPTATION OF THE SOMOGYI METHOD FOR THE DETERMINATION OF GLUCOSE , 1944 .

[10]  C. Foyer.  FEEDBACK INHIBITION OF PHOTOSYNTHESIS THROUGH SOURCE-SINK REGULATION IN LEAVES , 1988 .

[11]  U. Schreiber,et al.  Assessment of photosystem II photochemical quantum yield by chlorophyll fluorescence quenching analysis , 1995 .

[12]  D. Shimshi,et al.  Growth and yield studies of potato development in a semi-arid region. 3. Effect of water stress and amounts of nitrogen top dressing on physiological indices and on tuber yield and quality of several cultivars , 1985, Potato Research.

[13]  J. Vos,et al.  Photosynthesis and stomatal conductance of potato leaves—effects of leaf age, irradiance, and leaf water potential , 2004, Photosynthesis Research.

[14]  A. Schapendonk,et al.  Effects of water stress on photosynthesis and chlorophyll fluorescence of five potato cultivars , 1989, Potato Research.

[15]  M. Stitt,et al.  Coarse control of sucrose-phosphate synthase in leaves: Alterations of the kinetic properties in response to the rate of photosynthesis and the accumulation of sucrose , 1988, Planta.

[16]  A. Willis,et al.  The estimation of carbohydrates in plant extracts by anthrone. , 1954, The Biochemical journal.

[17]  P. Quick,et al.  Short-term water stress leads to a stimulation of sucrose synthesis by activating sucrose-phosphate synthase , 1989, Planta.