title: Differential Roles of PIN1 and PIN2 in Root Meristem Maintenance Under Low-B Conditions in Arabidopsis thaliana.
abstract: Boron (B) is an essential element for plants; its deficiency causes rapid cessation of root elongation. In addition, B influences auxin accumulation in plants. To assess the importance of auxin transport in B-dependent root elongation, Arabidopsis thaliana pin1-pin4 mutants were grown under low-B conditions. Among them, only the pin2/eir1-1 mutant showed a significantly shorter root under low-B conditions than under control conditions. Moreover, the root meristem size of pin2/eir1-1 was reduced under low-B conditions. Among the PIN-FORMED (PIN) family, PIN1 and PIN2 are important for root meristem growth/maintenance under normal conditions. To investigate the differential response of pin1 and pin2 mutants under low-B conditions, the effect of low-B on PIN1-green fluorescent protein (GFP) and PIN2-GFP accumulation and localization was examined. Low-B did not affect PIN2-GFP, while it reduced the accumulation of PIN1-GFP. Moreover, no signal from DII-VENUS, an auxin sensor, was detected under the low-B condition in the stele of wild-type root meristems. Taken together, these results indicate that under low-B conditions PIN1 is down-regulated and PIN2 plays an important role in root meristem maintenance.
authors: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan.
authors: Ke
authors: K
authors: Li
authors: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan.
authors: Takehiro
authors: T
authors: Kamiya
authors: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan atorufu@mail.ecc.u-tokyo.ac.jp.
authors: Toru
authors: T
authors: Fujiwara
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001895:Boron / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D018519:Meristem / Q000187:drug effects / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009929:Organ Size / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D001895:Boron; D049452:Green Fluorescent Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; C116363:PIN1 protein, Arabidopsis; C117013:AT5G57090 protein, Arabidopsis
keywords: Boron deficiency; PIN1; PIN2; Root meristem