Display options
Share it on

Plant Physiol. 1992 Oct;100(2):733-9. doi: 10.1104/pp.100.2.733.

Effects of Water-Deficit Stress on Photosynthesis, Its Components and Component Limitations, and on Water Use Efficiency in Wheat (Triticum aestivum L.).

Plant physiology

B Martin, N A Ruiz-Torres

Affiliations

  1. Department of Agronomy, Oklahoma State University, Stillwater, Oklahoma 74078-0507.

PMID: 16653053 PMCID: PMC1075620 DOI: 10.1104/pp.100.2.733

Abstract

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 CO(2) and H(2)O 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 CO(2)-saturated A, and stomatal conductance (g(s)) components. The limitations on A measured at ambient CO(2) concentration (A(350)) were estimated. No cultivar difference was observed when A(350) was plotted versus leaf water potential (Psi(w)). Light- and CO(2)-saturated A, c.e., and g(s) decreased with decreasing leaf Psi(w), but of the corresponding photosynthesis limitations only those caused by insufficient c.e. and g(s) increased. Thus, reduced stomatal aperture and Calvin cycle activity, but not electron transport/photophosphorylation, appeared to be major reasons for drought stress-induced inhibition of A(350). WUE measured as A(350)/g(s) first increased with stomatal closure down to a g(s) of about 0.25 mol H(2)O m(-2) s(-1) (Psi(w) = -1.6 MPa). However, it was predicted that A(350)/g(s) would decrease with more severe stress due to inhibition of c.e.

References

  1. Plant Physiol. 1988 Sep;88(1):213-7 - PubMed
  2. Science. 1989 Mar 31;243(4899):1725-8 - PubMed
  3. Plant Physiol. 1989 Apr;89(4):1066-70 - PubMed
  4. Plant Physiol. 1984 Jan;74(1):161-6 - PubMed
  5. Plant Physiol. 1974 Mar;53(3):474-9 - PubMed
  6. Science. 1982 Oct 29;218(4571):443-8 - PubMed

Publication Types