| Plant roots have many functions. They can fix plant, absorb water and mineral nutrition from the soil,transport nutrition, breed and store nutrition. At the same time plant roots play an important role inperceiving a variety of stress from the outside world. The formation of plant roots are related to manyinternal and external factors, especially plant hormones such as auxin, gibberellins, ABA etc. There weredetailed studies on the mechanism of signal transduction on the roots of plants in recent years, but very fewstudy on the mechanism of the ABA inhibition primary root growth in Arabidopsis, especially in theunderstanding of the changes in gene expression.In this study the experimental material was obtained by EMS mutagenesis and screened on MS mediumcontaining5μM ABA, which was a root growth defective mutant. And we named this mutant as a primaryroot short mutant e44. The primary root of e44was much shorter than that of wild type on5μM ABAmedium; Germination experiment showed e44mutant was insensitivity to ABA; through far-infraredexperiment, the dehydration test and stomatal observation,we found e44stomatal aperture was smaller andthe surface temperature of e44was higher0.83°C than that of wild type. These results suggested that theE44gene not only regulated Arabidopsis primary root morphogenesis, but also involved in seedgermination, stomatal aperture and other classic ABA response. The genetic analysis showed that e44was asingle recessive mutant. Finally, the mutation site of e44was positioned on the BAC of F18B13bymap-based cloning.Based on the above experimental results, the mutant e44had the classic ABA response physiologicalphenotype, suggesting E44gene was involved in the ABA regulation of Arabidopsis root morphogenesisand the E44gene played a very important role in the regulation of plant root development. TheIdentification and cloning of e44will lay foundation for studying the deep mechanism of theABA-regulated primary root growth and development. |
PDF Full Text Request