title: Genetic control of leaf-blade morphogenesis by the INSECATUS gene in Pisum sativum.
abstract: To understand the role of INSECATUS (INS) gene in pea, the leaf blades of wild-type, ins mutant and seven other genotypes, constructed by recombining ins with uni-tac, af, tl and mfp gene mutations, were quantitatively compared. The ins was inherited as a recessive mutant allele and expressed its phenotype in proximal leaflets of full size leaf blades. In ins leaflets, the midvein development was arrested in distal domain and a cleft was formed in lamina above this point. There was change in the identity of ins leaflets such that the intercalary interrupted midvein bore a leaf blade. Such adventitious blades in ins, ins tl and ins tl mfp were like the distal segment of respective main leaf blade. The ins phenotype was not seen in ins af and ins af uni-tac genotypes. There was epistasis of uni-tac over ins. The ins, tl and mfp mutations interacted synergistically to produce highly pronounced ins phenotype in the ins tl mfp triple mutant. The role(s) of INS in leaf-blade organogenesis are: positive regulation of vascular patterning in leaflets, repression of UNI activity in leaflet primordia for ectopic growth and in leaf-blade primordium for indeterminate growth of rachis, delimitation of proximal leaflet domain and together with TL and MFP homeostasis for meristematic activity in leaflet primordia. The variant apically bifid shape of the affected ins leaflets demonstrated that the leaflet shape is dependent on the venation pattern.
authors.affiliation: National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110 067, India. sushil2000_01@yahoo.co.in
authors.forename: Sushil
authors.initials: S
authors.lastname: Kumar
authors.forename: Swati
authors.initials: S
authors.lastname: Chaudhary
authors.forename: Vishakha
authors.initials: V
authors.lastname: Sharma
authors.forename: Renu
authors.initials: R
authors.lastname: Kumari
authors.forename: Raghvendra Kumar
authors.initials: RK
authors.lastname: Mishra
authors.forename: Arvind
authors.initials: A
authors.lastname: Kumar
authors.forename: Debjani Roy
authors.initials: DR
authors.lastname: Choudhury
authors.forename: Ruchi
authors.initials: R
authors.lastname: Jha
authors.forename: Anupama
authors.initials: A
authors.lastname: Priyadarshini
authors.forename: Arun
authors.initials: A
authors.lastname: Kumar
mesh_terms: D004843:Epistasis, Genetic / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics*; D005838:Genotype; D007194:India; D009154:Mutation; D018532:Pisum sativum / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D018515:Plant Leaves / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development