The genetics of gravitropism in Arabidopsis thaliana root development скачать в хорошем качестве

The genetics of gravitropism in Arabidopsis thaliana root development

The axr4 auxin-resistant mutants of Arabidopsis thaliana define a gene important for root gravitropism and lateral root initiation. Hobbie L, Estelle M. Plant J. 1995 Feb;7(2):211-20. doi: 10.1046/j.1365-313x.1995.7020211.x. OTHER VIDEOS YOU MIGHT LIKE: • Free garden fertiliser: symbiosis between legumes and Rhizobium leguminosarum -    • Free garden fertiliser: symbiosis between ...   • Taq polymerase: The workhorse of PCR. Neigh!!! -    • Taq polymerase: The workhorse of PCR. Neig...   • Are broccoli, cabbage and cauliflower the same? The evolution of domesticated cruciferous vegetables -    • Видео   The growth and development of plants depends on proper nutrition and external factors such as water, sunlight and gravity. Here we explain the importance of genes in root development and root gravitropism. Gravitropism is a phenomenon by which the parts of the plants grow downwards due to the force of gravity. Auxins are certain chemicals that help in the growth and development of plants and they also stimulate cell division. Auxins are mainly produced in the root tips, shoots and buds. The production and sensitivity of auxins is dependent on certain genes that are present in plants. Lawrence Hobbie and Mark Estelle studied Arabidopsis thaliana to correlate the importance of genes and growth and development of plants. A new locus related to auxin response was found in the Arabidopsis thaliana and it was named as axr4. Mutation of this gene led to auxin resistance in plants, further leading to decrease in lateral root formation, slower root gravitropism, and root elongation. Two other loci relating to auxin response was found in the Arabidopsis thaliana plant termed as aux1 and axr1. To establish a relationship between aux1, axr1 and axr4 double mutants were considered. The axr4-axr1 double mutant was found to be synergistic with each other and had slower lateral root development. The axr4-aux1 double mutant had an additive effect with respect to lateral root formation, it was shown to form very fewer lateral roots. The axr4-aux1 double mutant was found to be less auxin resistant than axr4-axr1 double mutant. Even though the axr4-axr1 double mutant is sensitive to auxin it showed very less root gravitropism indicating that lateral root formation needed more auxin sensitivity than root gravitropism. There was more root elongation found in the axr4 mutant plants in a span of seven days than when compared to the wild type. Hence we could conclude that the axr4, axr1 and aux1 gene protein products are involved in auxin response which in turn plays a major role in root gravitropism and lateral root development. Creator: Nithya Bhat References: Hobbie L, Estelle M. The axr4 auxin-resistant mutants of Arabidopsis thaliana define a gene important for root gravitropism and lateral root initiation. Plant J. 1995;7(2):211-220. Burström, H.G. Influence of the tonic effect of gravitation and auxin on cell elongation and polarity in roots. Am J Bot 1969;56(7):679-684. Evans ML, Ishikawa H, Estelle MA. Responses of Arabidopsis roots to auxin studied with high temporal resolution: Comparison of wild type and auxin-response mutants. Planta. 1994;194:215-222. Lincoln C, Britton JH, Estelle M. Growth and development of the axr1 mutants of Arabidopsis. Plant Cell. 1990;2(11):1071-1080. Pickett FB, Wilson AK, Estelle M. The aux1 mutation of Arabidopsis confers both auxin and ethylene resistance. Plant Physiol. 1990;94(3):1462-146.