| Abstract Detail
Salinity Zhan, Xiangqiang [1], Bressan, Ray A. [2], Hasegawa, Paul M. [2]. Pyruvate kinase-like HGCs control stress responsive seed germination in Thellungiella halophila and Arabidopsis thaliana. Germination of seeds of Thellungiella halophila (SHANGDONG, a halophyte) are inhibited by high NaCl, much more than those of Arabidopsis thaliana (Col-0, a glycophyte). A T. halophila T-DNA activation tagged population was screened for mutants with high germination capacity (hgc) under high NaCl stress and hgc1-1 was identified. hgc1-1 accumulates an elevated aberrant transcript that contains a putative ThHGC1 open reading frame (ORF). ThHGC1 encodes a putative pyruvate kinase (PK). Knock-out mutations in Arabidopsis of two genes that are most identical to ThHGC1 were identified in the A. thaliana T-DNA insertion populations and named Athgc1-2, Athgc2-1. Compared to wild type Col-0, germination of Athgc1-2 shows increased sensitivity to NaCl and ABA, whereas hgc2 is more tolerant. As expected, over-expression of the AtHGC1 coding sequence in Col-0 results in increased tolerance of seed germination to NaCl and ABA. These results indicate that HGC genes control seed germination responses to NaCl and ABA in plants. Conservation of these gene sequences that maintain similar function in both the halophyte and glycophyte may be indicative that HGCs are critical to the fitness of T. halophila to its native saline environment. A hypothesis is that HGCs may coordinate ABA and sugar signaling pathways that regulate seed germination in response to NaCl stress.
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1 - Center for Plant Environmental Stress Physiology, Dept. of Horticulture and Landscape Architecture, 625 Agriculture Mall Drive, West Lafayette, IN, 47907-2010, USA
2 - Center for Plant Environmental Stress Physiology, Dept. of Horticulture and Landscape Architecture
Keywords:
salinity
seed germination
ABA
sugar signaling
Thellungiella halophila
Arabidopsis thaliana
high germination capacity (HGC)
pyruvate kinase.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P07016
Abstract ID:2535 |
