Recently the porA-1 null mutant of Arabidopsis thaliana has been identified, which contains an insertion of the Dissociation (Ds) element in the PORA gene (Paddock et al. in Plant Mol Biol 78:447–460, 2012). Light-grown porA-1 seedlings suffer from a drastically reduced chlorophyll content and a developmental arrest beyond the cotyledon stage, suggesting that PORA is not only transiently involved in initiating chlorophyll synthesis during illumination of etiolated seedlings but is also essential for normal growth and plant development. Here we report the presence of a second Ds element in this porA-1 mutant line that inactivates the Speechless gene required for stomata formation. Similar to porA-1, speechless seedlings are severely impaired in their development. Our results suggest that the lack of stomata in porA-1 may contribute to the dwarfed phenotype of the mutant and thus emphasizes the need to re-address the proposed role of PORA during plant development by studying a porA mutant that retains its stomata formation.
NADPH: protochlophyllide oxidoreductase A SpeechlessSeedling development Chlorophyll synthesis
This is a preview of subscription content, log in to check access.
We thank Dr. Troy Paddock for sending us seeds of the porA-1 mutant and for helpful discussions. This study was supported by the Boyce Thompson Institute for Plant Research.
Conflict of interest
The authors declare that they have no conflict of interest.
Escobar-Restrepo JM, Huck N, Kessler S, Gagliardini V, Gheyselinck J, Yang WC, Grossniklaus U (2007) The FERONIA receptor-like kinase mediates male-female interactions during pollen tube reception. Science 317:656–660PubMedCrossRefGoogle Scholar
Frick G, Su Q, Apel K, Armstrong GA (2003) An Arabidopsis porB porC double mutant lacking light-dependent NADPH: protochlorophyllide oxidoreductases B and C is highly chlorophyll-deficient and developmentally arrested. Plant J 35:141–153PubMedCrossRefGoogle Scholar
MacAlister CA, Ohashi-Ito K, Bergmann DC (2007) Transcription factor control of asymmetric cell divisions that establish the stomatal lineage. Nature 445:537–540PubMedCrossRefGoogle Scholar
Masuda T, Takamiya K (2004) Novel insights into the enzymology, regulation and physiological functions of light-dependent protochlorophyllide oxidoreductase in angiosperms. Photosynth Res 81:1–29PubMedCrossRefGoogle Scholar
Paddock T, Mason ME, Lima DF, Armstrong GA (2010) Arabidopsis protochlorophyllide oxidoreductase A (PORA) restores bulk chlorophyll synthesis and normal development to a porB porC double mutant. Plant Mol Biol 72:445–457PubMedCrossRefGoogle Scholar
Paddock T, Lima D, Mason ME, Apel K, Armstrong GA (2012) Arabidopsis light-dependent protochlorophyllide oxidoreductase A (PORA) is essential for normal plant growth and development. Plant Mol Biol 78:447–460PubMedCrossRefGoogle Scholar
Pillitteri LJ, Sloan DB, Bogenschutz NL, Torii KU (2007) Termination of asymmetric cell division and differentiation of stomata. Nature 445:501–505PubMedCrossRefGoogle Scholar
Sperling U, van Cleve B, Frick G, Apel K, Armstrong GA (1997) Overexpression of light-dependent PORA or PORB in plants depleted of endogenous POR by far-red light enhances seedling survival in white light and protects against photooxidative damage. Plant J 12:649–658PubMedCrossRefGoogle Scholar
Su Q, Frick G, Armstrong GA, Apel K (2001) PORC of Arabidopsis thaliana: a third light- and NADPH-dependent protochlorophyllide oxidoreductase that is differentially regulated by light. Plant Mol Biol 47:805–813PubMedCrossRefGoogle Scholar