title: Solanum lycopersicum IAA15 functions in the 2,4-dichlorophenoxyacetic acid herbicide mechanism of action by mediating abscisic acid signalling.
abstract: 2,4-Dichlorophenoxyacetic acid (2,4-D), an important plant growth regulator, is the herbicide most commonly used worldwide to control weeds. However, broad-leaf fruits and vegetables are extremely sensitive to herbicides, which can cause damage and result in lost crops when applied in a manner inconsistent with the directions. Despite detailed knowledge of the mechanism of 2,4-D, the regulation of auxin signalling is still unclear. For example, although the major mediators of auxin signalling, including auxin/indole acetic acid (AUX/IAA) proteins and auxin response factors (ARFs), are known to mediate auxinic herbicides, the underlying mechanisms are still unclear. In this study, the effects of 2,4-D on AUX/IAA gene expression in tomato were investigated, and the two most notably up-regulated genes, SlIAA15 and SlIAA29, were selected for further study. Western blotting revealed the substantial accumulation of both SlIAA15 and SlIAA29, and the expression levels of the corresponding genes were increased following abscisic acid (ABA) and ethylene treatment. Overexpressing SlIAA15, but not SlIAA29, induced a 2,4-D herbicide damage phenotype. The 35S::SlIAA15 line exhibited a strong reduction in leaf stomatal density and altered expression of some R2R3 MYB genes that are putatively involved in the regulation of stomatal differentiation. Further study revealed that root elongation in 35S::SlIAA15 was sensitive to ABA treatment, and was most probably due to the altered expression of an ABA signal transduction gene. In addition, the altered auxin sensitivities of SlIAA15 transformants were also explored. These results suggested that SlIAA15 plays an important role in determining the effects of the herbicide 2,4-D.
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang 110866, Liaoning, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang 110866, Liaoning, People's Republic of China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang 110866, Liaoning, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: Liaoning Cash Crop Institute, Liaoyang 111304, People's Republic of China.
authors.forename: Song
authors.initials: S
authors.lastname: Gao
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang 110866, Liaoning, People's Republic of China.
authors.forename: Mingfang
authors.initials: M
authors.lastname: Qi
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang 110866, Liaoning, People's Republic of China sonymiss1981@gmail.com.
authors.forename: Tianlai
authors.initials: T
authors.lastname: Li
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology*; D000040:Abscisic Acid / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D050437:Genes, Developmental; D017343:Genes, Plant; D006540:Herbicides / Q000494:pharmacology*; D018551:Solanum lycopersicum / Q000033:anatomy & histology / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005810:Multigene Family; D010641:Phenotype; D018515:Plant Leaves / Q000033:anatomy & histology / Q000187:drug effects / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D054046:Plant Stomata / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D034622:RNA Interference; D060888:Real-Time Polymerase Chain Reaction; D020539:Sequence Analysis, Protein; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics; D014170:Transformation, Genetic / Q000187:drug effects
chemical_list: D006540:Herbicides; D010940:Plant Proteins; D015084:2,4-Dichlorophenoxyacetic Acid; D000040:Abscisic Acid
keywords: 2,4-dichlorophenoxyacetic acid (2,4-D); ABA; AUX/IAA; auxin; herbicide; stoma density; tomato.