title: The EAR motif controls the early flowering and senescence phenotype mediated by over-expression of SlERF36 and is partly responsible for changes in stomatal density and photosynthesis.
abstract: The EAR motif is a small seven amino acid motif associated with active repression of several target genes. We had previously identified SlERF36 as an EAR motif containing gene from tomato and shown that its over-expression results in early flowering and senescence and a 25-35% reduction of stomatal density, photosynthesis and stomatal conductance in transgenic tobacco. In order to understand the role of the EAR motif in governing the phenotypes, we have expressed the full-length SlERF36 and a truncated form, lacking the EAR motif under the CaMV35S promoter, in transgenic Arabidopsis. Plants over-expressing the full-length SlERF36 show prominent early flowering under long day as well as short day conditions. The early flowering leads to an earlier onset of senescence in these transgenic plants which in turn reduces vegetative growth, affecting rosette, flower and silique sizes. Stomatal number is reduced by 38-39% while photosynthesis and stomatal conductance decrease by about 30-40%. Transgenic plants over-expressing the truncated version of SlERF36 (lacking the C-terminal EAR motif), show phenotypes largely matching the control with normal flowering and senescence indicating that the early flowering and senescence is governed by the EAR motif. On the other hand, photosynthetic rates and stomatal number were also reduced in plants expressing SlERF36ΔEAR although to a lesser degree compared to the full- length version indicating that these are partly controlled by the EAR motif. These studies show that the major phenotypic changes in plant growth caused by over-expression of SlERF36 are actually mediated by the EAR motif.
authors.affiliation: Plant Gene Expression Lab, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow, India; Sustainable Agricultural Systems Laboratory, USDA-ARS, Beltsville Agricultural Research Center, Beltsville, Maryland, United States of America; Department of Biology, Pennsylvania State University, Harrisburg, Pennsylvania, United States of America.
authors.forename: Rakesh Kumar
authors.initials: RK
authors.lastname: Upadhyay
authors.affiliation: Plant Gene Expression Lab, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow, India.
authors.forename: Asmita
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Department of Plant Physiology, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow, India.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Ranjan
authors.affiliation: Department of Plant Physiology, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow, India.
authors.forename: Ruchi
authors.initials: R
authors.lastname: Singh
authors.affiliation: Department of Plant Physiology, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow, India.
authors.forename: Uday V
authors.initials: UV
authors.lastname: Pathre
authors.affiliation: Plant Gene Expression Lab, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow, India.
authors.forename: Pravendra
authors.initials: P
authors.lastname: Nath
authors.affiliation: Plant Gene Expression Lab, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow, India.
authors.forename: Aniruddha P
authors.initials: AP
authors.lastname: Sane
mesh_terms: D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D035264:Flowers / Q000254:growth & development*; D015870:Gene Expression; D018551:Solanum lycopersicum / Q000235:genetics; D010641:Phenotype; D017440:Photoperiod; D010788:Photosynthesis; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D054046:Plant Stomata / Q000254:growth & development*; D030821:Plants, Genetically Modified
chemical_list: D010940:Plant Proteins