Microdissection of shoot meristem functional domains.
The shoot apical meristem (SAM) maintains a pool of indeterminate cells within the SAM proper, while lateral organs are initiated from the SAM periphery. Laser microdissection-microarray technology was used to compare transcriptional profiles within these SAM domains to identify novel maize genes that function during leaf development. Nine hundred and sixty-two differentially expressed maize genes were detected; control genes known to be upregulated in the initiating leaf (P0/P1) or in the SAM proper verified the precision of the microdissections. Genes involved in cell division/growth, cell wall biosynthesis, chromatin remodeling, RNA binding, and translation are especially upregulated in initiating leaves, whereas genes functioning during protein fate and DNA repair are more abundant in the SAM proper. In situ hybridization analyses confirmed the expression patterns of six previously uncharacterized maize genes upregulated in the P0/P1. P0/P1-upregulated genes that were also shown to be downregulated in leaf-arrested shoots treated with an auxin transport inhibitor are especially implicated to function during early events in maize leaf initiation. Reverse genetic analyses of asceapen1 (asc1), a maize D4-cyclin gene upregulated in the P0/P1, revealed novel leaf phenotypes, less genetic redundancy, and expanded D4-CYCLIN function during maize shoot development as compared to Arabidopsis. These analyses generated a unique SAM domain-specific database that provides new insight into SAM function and a useful platform for reverse genetic analyses of shoot development in maize.
Department of Plant Biology, Cornell University, Ithaca, NY, USA.
Lionel
L
Brooks
Josh
J
Strable
Xiaolan
X
Zhang
Kazuhiro
K
Ohtsu
Ruilian
R
Zhou
Ananda
A
Sarkar
Sarah
S
Hargreaves
Robert J
RJ
Elshire
Douglas
D
Eudy
Teresa
T
Pawlowska
Doreen
D
Ware
Diane
D
Janick-Buckner
Brent
B
Buckner
Marja C P
MC
Timmermans
Patrick S
PS
Schnable
Dan
D
Nettleton
Michael J
MJ
Scanlon
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D056741:Cyclin D; D016213:Cyclins / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D030541:Databases, Genetic; D019143:Evolution, Molecular; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017403:In Situ Hybridization; D018519:Meristem / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D042282:Microdissection; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics; D013045:Species Specificity; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism
D056741:Cyclin D; D016213:Cyclins; D018744:DNA, Plant; D010940:Plant Proteins