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Indian Journal of Biotechnology (IJBT) >
IJBT Vol.02 [2003] >
IJBT Vol.02(1) [January 2003] >
| Title: | Hormonal Regulation of Moss Protonema Development and the Possible Origin of Plant Hormonal Responses in Bryophytes |
| Authors: | D'Souza, Jacinta S
Johri, M M |
| Keywords: | Funaria hygrometrica
Moss protonema
CDPKs
MBP kinase
Abscisic acid
Auxin
Calcium
Origin of hormonal responses |
| Issue Date: | Jan-2003 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | The protonema of mosses is a far simpler
paradigm to understand the mechanism of hormonal action and tolerance to
abiotic stresses in plants. Its developmental biology, responses to hormones
and the similarity of signaling mechanisms with higher plants are reviewed.
There is strong evidence for second messenger role of calcium ions in the
action of cytokinin. Multiple calcium-dependent protein kinases (CDPKs) are
present in the protonema. The Funaria hygrometrica CDPK gene (FhCDPK)
shows the characteristic catalytic and autoinhibitory domains, the four EF
hands and the highest homology to CDPKs from higher plants but far lower to
liverwort or other moss CDPK genes. A 38 kDa myelin basic protein kinase (MBP
kinase) is activated within minutes by abscisic acid (ABA) and salinity. As ABA
also confers tolerance against desiccation and freezing and the wheat
ABA-inducible promoter is fully functional in mosses, the ABA signaling mechanism seems to be highly
conserved. In plants, the CDPKs are involved not only in hormonal signaling but
also in the acclimation response against abiotic stresses. The manipulation of
signal transduction components such as transcription factors, CDPKs and
calcineurin have emerged as viable strategies to genetically engineer the
stress tolerant plants. There is increasing evidence to support the origin of
plant hormonal responses at the level of bryophytes. |
| Page(s): | 9-16 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-0967 (Online); 0972-5849 (Print) |
| Source: | IJBT Vol.02(1) [January 2003]
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