Acquisition of Desiccation Tolerance and Longevity in Seeds of Arabidopsis thaliana (A Comparative Study Using Abscisic Acid-Insensitive abi3 Mutants).

AUTOR(ES)

Ooms, JJJ.

RESUMO

Two new abscisic acid (ABA)-insensitive mutants of Arabidopsis thaliana affected in the abi3 locus are described. These new mutants are severely ABA insensitive. Like the earlier described abi3-1 and the ABA-deficient and -insensitive double mutant aba,abi3, these new mutants vary in the extent of ABA-correlated physiological responses. Mutant seeds fail to degrade chlorophyll during maturation and show no dormancy, and desiccation tolerance and longevity are poorly developed. Carbohydrate accumulation as well as synthesis of LEA or RAB proteins are often suggested to be essential for acquisition of desiccation tolerance. In this work two points are demonstrated. (a) Accumulation of carbohydrates as such does not correlate with acquisition of desiccation tolerance or longevity. It is suggested that a low ratio of mono- to oligosac-charides rather than the absolute amount of carbohydrates controls seed longevity or stability to desiccation tolerance. (b) Synthesis of a few assorted proteins, which is responsive to ABA in the later part of seed maturation, is not correlated with desiccation tolerance or longevity.

Documentos Relacionados

• Regulation and Role of the Arabidopsis Abscisic Acid-Insensitive 5 Gene in Abscisic Acid, Sugar, and Stress Response1
• Molecular Analysis of viviparous-1: An Abscisic Acid-Insensitive Mutant of Maize.
• The Arabidopsis ABSCISIC ACID-INSENSITIVE2 (ABI2) and ABI1 genes encode homologous protein phosphatases 2C involved in abscisic acid signal transduction.
• The Arabidopsis thaliana ABSCISIC ACID-INSENSITIVE8 Locus Encodes a Novel Protein Mediating Abscisic Acid and Sugar Responses Essential for GrowthW⃞
• Regulation of gene expression programs during Arabidopsis seed development: roles of the ABI3 locus and of endogenous abscisic acid.