Punctate vascular expression1 is a novel maize gene required for leaf pattern formation that functions downstream of the trans-acting small interfering RNA pathway.
The maize (Zea mays) gene RAGGED SEEDLING2-R (RGD2-R) encodes an ARGONAUTE7-like protein required for the biogenesis of trans-acting small interfering RNA, which regulates the accumulation of AUXIN RESPONSE FACTOR3A transcripts in shoots. Although dorsiventral polarity is established in the narrow and cylindrical leaves of rgd2-R mutant plants, swapping of adaxial/abaxial epidermal identity occurs and suggests a model wherein RGD2 is required to coordinate dorsiventral and mediolateral patterning in maize leaves. Laser microdissection-microarray analyses of the rgd2-R mutant shoot apical meristem identified a novel gene, PUNCTATE VASCULAR EXPRESSION1 (PVE1), that is down-regulated in rgd2-R mutant apices. Transcripts of PVE1 provide an early molecular marker for vascular morphogenesis. Reverse genetic analyses suggest that PVE1 functions during vascular development and in mediolateral and dorsiventral patterning of maize leaves. Molecular genetic analyses of PVE1 and of rgd2-R;pve1-M2 double mutants suggest a model wherein PVE1 functions downstream of RGD2 in a pathway that intersects and interacts with the trans-acting small interfering RNA pathway.
Plant Biology Department, University of Georgia, Athens, Georgia 30602, USA.
Xiaolan
X
Zhang
Ryan N
RN
Douglas
Josh
J
Strable
Michelle
M
Lee
Brent
B
Buckner
Diane
D
Janick-Buckner
Patrick S
PS
Schnable
Marja C P
MC
Timmermans
Michael J
MJ
Scanlon
D000483:Alleles; D019521:Body Patterning / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D017403:In Situ Hybridization; D061346:Laser Capture Microdissection; D018519:Meristem / Q000235:genetics; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics* / Q000254:growth & development*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D058526:Plant Vascular Bundle / Q000033:anatomy & histology / Q000166:cytology / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism*; D059386:Reverse Genetics; D015398:Signal Transduction / Q000235:genetics; D003313:Zea mays / Q000235:genetics*
D010940:Plant Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering