title: KNOTTED1 Cofactors, BLH12 and BLH14, Regulate Internode Patterning and Vein Anastomosis in Maize.
abstract: Monocot stems lack the vascular cambium and instead have characteristic structures in which intercalary meristems generate internodes and veins remain separate and scattered. However, developmental processes of these unique structures have been poorly described. BELL1-like homeobox (BLH) transcription factors (TFs) are known to heterodimerize with KNOTTED1-like homeobox TFs to play crucial roles in shoot meristem maintenance, but their functions are elusive in monocots. We found that maize (Zea mays) BLH12 and BLH14 have redundant but important roles in stem development. BLH12/14 interact with KNOTTED1 (KN1) in vivo and accumulate in overlapping domains in shoot meristems, young stems, and provascular bundles. Similar tokn1loss-of-function mutants,blh12 blh14(blh12/14) double mutants fail to maintain axillary meristems. Unique toblh12/14is an abnormal tassel branching and precocious internode differentiation that results in dwarfism and reduced veins in stems. Micro-computed tomography observation of vascular networks revealed thatblh12/14double mutants had reduced vein number due to fewer intermediate veins in leaves and precocious anastomosis in young stems. Based on these results, we propose two functions of BLH12/14 during stem development: (1) maintaining intercalary meristems that accumulate KN1 and prevent precocious internode differentiation and (2) preventing precocious anastomosis of provascular bundles in young stems to ensure the production of sufficient independent veins.
authors.affiliation: Experimental Farm, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.|Department of Genetics, School of Life Science, Graduate University for Advanced Studies, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Katsutoshi
authors.identifier: http://orcid.org/0000-0001-6325-5201
authors.initials: K
authors.lastname: Tsuda
authors.affiliation: Plant Gene Expression Center, U.S. Department of Agriculture-Agricultural Research Service, Plant and Microbial Biology Department, University of California at Berkeley, Albany, California 94710.
authors.forename: Maria-Jazmin
authors.identifier: http://orcid.org/0000-0002-5468-8176
authors.initials: MJ
authors.lastname: Abraham-Juarez
authors.affiliation: Mammalian Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.
authors.forename: Akiteru
authors.initials: A
authors.lastname: Maeno
authors.affiliation: Plant Gene Expression Center, U.S. Department of Agriculture-Agricultural Research Service, Plant and Microbial Biology Department, University of California at Berkeley, Albany, California 94710.
authors.forename: Zhaobin
authors.initials: Z
authors.lastname: Dong
authors.affiliation: Plant Gene Expression Center, U.S. Department of Agriculture-Agricultural Research Service, Plant and Microbial Biology Department, University of California at Berkeley, Albany, California 94710.
authors.forename: Dale
authors.initials: D
authors.lastname: Aromdee
authors.affiliation: Pioneer Hi-Bred International, Johnston, Iowa 50131.
authors.forename: Robert
authors.identifier: http://orcid.org/0000-0002-4496-1888
authors.initials: R
authors.lastname: Meeley
authors.affiliation: Department of Genetics, School of Life Science, Graduate University for Advanced Studies, Mishima, Shizuoka 411-8540, Japan.|Mammalian Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Shiroishi
authors.affiliation: Experimental Farm, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.|Department of Genetics, School of Life Science, Graduate University for Advanced Studies, Mishima, Shizuoka 411-8540, Japan.
authors.forename: Ken-Ichi
authors.identifier: http://orcid.org/0000-0002-2057-543X
authors.initials: KI
authors.lastname: Nonomura
authors.affiliation: Plant Gene Expression Center, U.S. Department of Agriculture-Agricultural Research Service, Plant and Microbial Biology Department, University of California at Berkeley, Albany, California 94710 hake@berkeley.edu.
authors.forename: Sarah
authors.identifier: http://orcid.org/0000-0001-6953-1529
authors.initials: S
authors.lastname: Hake
mesh_terms: D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D018519:Meristem / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins