title: Improvement of Arabidopsis Biomass and Cold, Drought and Salinity Stress Tolerance by Modified Circadian Clock-Associated PSEUDO-RESPONSE REGULATORs.
abstract: Plant circadian clocks control the timing of a variety of genetic, metabolic and physiological processes. Recent studies revealed a possible molecular mechanism for circadian clock regulation. Arabidopsis thaliana (Arabidopsis) PSEUDO-RESPONSE REGULATOR (PRR) genes, including TIMING OF CAB EXPRESSION 1 (TOC1), encode clock-associated transcriptional repressors that act redundantly. Disruption of multiple PRR genes results in drastic phenotypes, including increased biomass and abiotic stress tolerance, whereas PRR single mutants show subtle phenotypic differences due to genetic redundancy. In this study, we demonstrate that constitutive expression of engineered PRR5 (PRR5-VP), which functions as a transcriptional activator, can increase biomass and abiotic stress tolerance, similar to prr multiple mutants. Concomitant analyses of relative growth rate, flowering time and photosynthetic activity suggested that increased biomass of PRR5-VP plants is mostly due to late flowering, rather than to alterations in photosynthetic activity or growth rate. In addition, genome-wide gene expression profiling revealed that genes related to cold stress and water deprivation responses were up-regulated in PRR5-VP plants. PRR5-VP plants were more resistant to cold, drought and salinity stress than the wild type, whereas ft tsf and gi, well-known late flowering and increased biomass mutants, were not. These findings suggest that attenuation of PRR function by a single transformation of PRR-VP is a valuable method for increasing biomass as well as abiotic stress tolerance in Arabidopsis. Because the PRR gene family is conserved in vascular plants, PRR-VP may regulate biomass and stress responses in many plants, but especially in long-day annual plants.
authors.affiliation: Institute of Transformative Bio-Molecules, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 Japan Graduate School of Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 Japan Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama, 332-0022 Japan nnakamichi@itbm.nagoya-u.ac.jp.
authors.forename: Norihito
authors.initials: N
authors.lastname: Nakamichi
authors.affiliation: Institute of Transformative Bio-Molecules, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Takao
authors.affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22, Suehiro, Tsurumi, Yokohama, 230-0045 Japan School of Agriculture, Meiji University, Kawasaki, 214-8571 Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kudo
authors.affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22, Suehiro, Tsurumi, Yokohama, 230-0045 Japan.
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Kiba
authors.affiliation: Institute of Transformative Bio-Molecules, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 Japan Institute for Advanced Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 Japan.
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Transformative Bio-Molecules, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 Japan Graduate School of Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Kinoshita
authors.affiliation: RIKEN Center for Sustainable Resource Science, 1-7-22, Suehiro, Tsurumi, Yokohama, 230-0045 Japan RIKEN Biomass Engineering Program Cooperation Division, 1-7-22, Suehiro, Tsurumi, Yokohama, 230-0045 Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sakakibara
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018533:Biomass; D057906:Circadian Clocks; D055864:Droughts; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D008027:Light; D010641:Phenotype; D054712:Salinity; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C523307:PRR5 protein, Arabidopsis; C411822:TOC1 protein, Arabidopsis; D014157:Transcription Factors
keywords: Arabidopsis thaliana; Biomass; Circadian clock; PRR