Genetic manipulation of stomatal density influences stomatal size, plant growth and tolerance to restricted water supply across a growth carbon dioxide gradient.
To investigate the impact of manipulating stomatal density, a collection of Arabidopsis epidermal patterning factor (EPF) mutants with an approximately 16-fold range of stomatal densities (approx. 20-325% of that of control plants) were grown at three atmospheric carbon dioxide (CO(2)) concentrations (200, 450 and 1000 ppm), and 30 per cent or 70 per cent soil water content. A strong negative correlation between stomatal size (S) and stomatal density (D) was observed, suggesting that factors that control D also affect S. Under some but not all conditions, mutant plants exhibited abnormal stomatal density responses to CO(2) concentration, suggesting that the EPF signalling pathway may play a role in the environmental adjustment of D. In response to reduced water availability, maximal stomatal conductance was adjusted through reductions in S, rather than D. Plant size negatively correlated with D. For example, at 450 ppm CO(2) EPF2-overexpressing plants, with reduced D, had larger leaves and increased dry weight in comparison with controls. The growth of these plants was also less adversely affected by reduced water availability than plants with higher D, indicating that plants with low D may be well suited to growth under predicted future atmospheric CO(2) environments and/or water-scarce environments.
Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
Timothy
T
Doheny-Adams
Lee
L
Hunt
Peter J
PJ
Franks
David J
DJ
Beerling
Julie E
JE
Gray
D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics; D002245:Carbon Dioxide / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005818:Genetic Engineering; D019441:Plant Epidermis / Q000737:chemistry / Q000235:genetics; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics / Q000254:growth & development; D054046:Plant Stomata / Q000737:chemistry / Q000235:genetics / Q000254:growth & development*; D018526:Plant Transpiration; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000235:genetics / Q000254:growth & development; D015398:Signal Transduction; D012987:Soil / Q000737:chemistry; D013696:Temperature; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics; D014867:Water / Q000737:chemistry
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C547253:EPF1 protein, Arabidopsis; C542689:EPF2 protein, Arabidopsis; C551854:EPFL9 protein, Arabidopsis; D012987:Soil; D014157:Transcription Factors; D014867:Water; D002245:Carbon Dioxide