title: Transport of boron by the tassel-less1 aquaporin is critical for vegetative and reproductive development in maize.
abstract: The element boron (B) is an essential plant micronutrient, and B deficiency results in significant crop losses worldwide. The maize (Zea mays) tassel-less1 (tls1) mutant has defects in vegetative and inflorescence development, comparable to the effects of B deficiency. Positional cloning revealed that tls1 encodes a protein in the aquaporin family co-orthologous to known B channel proteins in other species. Transport assays show that the TLS1 protein facilitates the movement of B and water into Xenopus laevis oocytes. B content is reduced in tls1 mutants, and application of B rescues the mutant phenotype, indicating that the TLS1 protein facilitates the movement of B in planta. B is required to cross-link the pectic polysaccharide rhamnogalacturonan II (RG-II) in the cell wall, and the percentage of RG-II dimers is reduced in tls1 inflorescences, indicating that the defects may result from altered cell wall properties. Plants heterozygous for both tls1 and rotten ear (rte), the proposed B efflux transporter, exhibit a dosage-dependent defect in inflorescence development under B-limited conditions, indicating that both TLS1 and RTE function in the same biological processes. Together, our data provide evidence that TLS1 is a B transport facilitator in maize, highlighting the importance of B homeostasis in meristem function.
authors.affiliation: Division of Biological Sciences, Bond Life Sciences Center, Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri 65211.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Durbak
authors.affiliation: Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Phillips
authors.affiliation: Division of Plant Sciences, Bond Life Sciences Center, Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri 65211.
authors.forename: Sharon
authors.initials: S
authors.lastname: Pike
authors.affiliation: Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602.
authors.forename: Malcolm A
authors.initials: MA
authors.lastname: O'Neill
authors.affiliation: Department of Biological Sciences, California State University, Long Beach, California 90840.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Mares
authors.affiliation: Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854.
authors.forename: Andrea
authors.initials: A
authors.lastname: Gallavotti
authors.affiliation: Department of Biological Sciences, California State University, Long Beach, California 90840.
authors.forename: Simon T
authors.initials: ST
authors.lastname: Malcomber
authors.affiliation: Division of Plant Sciences, Bond Life Sciences Center, Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri 65211.
authors.forename: Walter
authors.initials: W
authors.lastname: Gassmann
authors.affiliation: Division of Biological Sciences, Bond Life Sciences Center, Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri 65211 mcsteenp@missouri.edu.
authors.forename: Paula
authors.initials: P
authors.lastname: McSteen
mesh_terms: D000818:Animals; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D001881:Borates / Q000378:metabolism*; D001895:Boron / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006706:Homeostasis; D056626:Inflorescence / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018519:Meristem / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D009154:Mutation; D009865:Oocytes; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D030821:Plants, Genetically Modified; D012098:Reproduction; D014982:Xenopus laevis; D003313:Zea mays / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000502:physiology
chemical_list: D020346:Aquaporins; D001881:Borates; D010940:Plant Proteins; D001895:Boron