TY  - JA
AU  - Martin,B.
AU  - Ruiz Torres,N.A.
TI  - Effects of water-deficit stress on photosynthesis, its components and component limitations, and on water use efficiency in wheat (Triticum aestivum L.)
SN  - 0032-0889
U1  - 94-107860 
PY  - 1992///
KW  - Biochemical pathways
KW  - Biochemical reactions
KW  - Biosynthesis
KW  - Chemical reactions
KW  - Energy metabolism
KW  - Epidermis
KW  - Gramineae
KW  - Metabolism
KW  - Miscellaneous plant disorders
KW  - Oxides
KW  - Physiological functions
KW  - Plant anatomy
KW  - AGROVOC
KW  - Plant physiology
KW  - Plant physiology and biochemistry
KW  - Plant tissues
KW  - Plant vegetative organs
KW  - Resource management
KW  - Stress
KW  - Water
KW  - Water balance
KW  - Triticum
N1  - references US (DNAL 450 P692)
N2  - It is of theoretical as well as practical interest to identify the components of the photosynthetic machinery that govern variability in photosynthesis rate (A) and water-use efficiency (WUE), and to define the extent by which the component processes limit A and WUE during developing water-deficit stress. For that purpose, leaf exchange of CO2 and H2O was determined in two growth-chamber-grown wheat cultivars (Triticum aestivum L. cv TAM W-101 and cv Sturdy), and the capacity of A was determined and broken down into carboxylation efficiency (c.e.), light- and CO2-saturated A, and stomatal conductance (gs) components. The limitations on A measured at ambient CO2 concentration (A350) were estimated. No cultivar difference was observed when A350 was plotted versus leaf water potential. Light- and CO2-saturated A, c.e., and gs decreased with decreasing leaf water potential but of the corresponding photosynthesis limitations only those caused by insufficient c.e. and gs increased. Thus, reduced stomatal a perture and Calvin cycle activity, but not electron transport/photophosphorylation, appeared to be major reasons for drought stress-induced inhibition of A350-WUE measured as A350/gs first increased with stomatal closure down to a gs of about 0.25 mol H2O m-2 s-1 (water potential = -1.6 MPa). However, it was predicted that A350/gs would decrease with more severe stress due to inhibition of c.e
T2  - Plant physiology (USA). (Oct 1992). v. 100(2) p. 733-739
ER  -