Details

Autor(en) / Beteiligte

• Bueso, Eduardo
• Muñoz‐Bertomeu, Jesús
• Campos, Francisco
• Martínez, Cándido
• Tello, Carlos
• Martínez‐Almonacid, Irene
• Ballester, Patricia
• Simón‐Moya, Miguel
• Brunaud, Veronique
• Yenush, Lynne
• Ferrándiz, Cristina
• Serrano, Ramón

Titel

Arabidopsis COGWHEEL1 links light perception and gibberellins with seed tolerance to deterioration

Ist Teil von

• The Plant journal : for cell and molecular biology, 2016-09, Vol.87 (6), p.583-596

Ort / Verlag

England: Blackwell Publishing Ltd

Erscheinungsjahr

2016

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Summary Light is a major regulator of plant growth and development by antagonizing gibberellins (GA), and we provide evidence for a role of light perception and GA in seed coat formation and seed tolerance to deterioration. We have identified two activation‐tagging mutants of Arabidopsis thaliana, cog1‐2D and cdf4‐1D, with improved seed tolerance to deterioration linked to increased expression of COG1/DOF1.5 and CDF4/DOF2.3, respectively. These encode two homologous DOF transcription factors, with COG1 most highly expressed in seeds. Improved tolerance to seed deterioration was reproduced in transgenic plants overexpressing these genes, and loss of function from RNA interference resulted in opposite phenotypes. Overexpressions of COG1 and CDF4 have been described to attenuate various light responses mediated by phytochromes. Accordingly, we found that phyA and phyB mutants exhibit increased seed tolerance to deterioration. The phenotype of tolerance to deterioration conferred by gain of function of COG1 and by loss of function of phytochromes is of maternal origin, is also observed under natural aging conditions and correlates with a seed coat with increased suberin and reduced permeability. In developing siliques of the cog1‐2D mutant the expression of the GA biosynthetic gene GA3OX3 and levels of GA1 are higher than in the wild type. These results explain the antagonism between phytochromes and COG1 in terms of the inhibition and the activation, respectively, of GA action. Significance Statement Seed tolerance to deterioration depends on anti‐aging defenses only partially understood. COG1 encodes a transcription factor previously described to attenuate phytochrome responses to light and we found that it is a positive regulator of seed tolerance to deterioration while light perception by phytochromes is negative. The proposed mechanism is that COG1 increases gibberellins levels, leading to a seed coat containing more suberin and less permeable to oxygen. Light is known to inhibit gibberellins action.