Effect of hormone Indole-3-acetic acid (IAA) associated with PGPR in response to root growth and development of tobacco (Nicotiana tabacum) Muhammad Yusril Hardiansyah (a,d*), Imam Imroni (b), Muhammad Aswad Ashan (c,d) Novaty Eny Dungga (d)
a) Global Agriculture Technology and Genomic Science, International College, National Taiwan University, Taipei 10617, Taiwan
*yusrilhardiansyah1[at]gmail.com
b) Agricultural Economics, College of Bio-Resources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
c) Plant Breeding and Biotechnology, Graduate School of IPB University (Bogor Agricultural University) Bogor 11680, Indonesia
d) Department of Agronomy, Agrotechnology Study Program, Faculty of Agriculture, Universitas Hasanuddin, Makassar 90245, Indonesia
Abstract
Indole-3-acetic acid (IAA) is widely associated with the plant growth-promoting rhizobacteria (PGPR) as the primary member of the auxins family produced by plants as it plays an essential role in the response of plant activities particularly in root initiation and development, shoot growth, etc. IAA cultivates in the enhancement of root length with an increase in the number of root branches, root hairs, and root laterals that aid in the uptake of nutrients from the surrounding. This study aims to decipher the response of root growth and development of tobacco inoculated by IAA hormones. Using PGPR as a primary association of bacterial group for IAA hormone, PGPR was colonized from the bamboo rhizosphere. PGPR was inoculated into the soil during seedling stages of tobacco with one to four times inoculation on 7, 14, 21, and 28 days after germination and measured the root observation until 35 days old of tobacco. The parameter observations include root length, root wet weight, root dry weight, root branches, and root hairs with three biological replicates. The form of Tukey^s test (one-way ANOVA) with SD was used as statistical analysis. The results shown IAA hormone successfully enhanced root length (30.62 cm), root wet weight (0.34 g), root dry weight (0.16 g), number of root branches (33), number of root hairs (726) after four times inoculation instead of one to three times and control treatment of IAA inoculation. To summarize this research, IAA associated with PGPR successfully enhances the root growth of tobacco after four times inoculation. Eventually, the IAA hormone plays an important role in response to root growth and development in tobacco.
