Roles of theAfandTlgenes in pea leaf morphogenesis: leaf morphology and pinna anatomy of the heterozygotes

Abstract

The leaf blade of Pisum sativum L. possesses proximal leaflets and distal tendrils and is altered by two recessive mutations that affect pinna identity, afila (af) and acacia/tendrilless (tl). Using morphological and histology features we characterized the variation in leaf form and pinna anatomy of the Af and Tl heterozygous genotypes. Our goal was to identify the specific interactions of these genes and the relative influence of each in regulating all structural components of the leaf and pinna phenotypes. The Tl/tl genotypes possess broad tendril - narrow leaflets in the distal region that are histologically more similar to leaflets than to tendrils. The afafTltl leaves have simple tendrils in the distal region and branching complexity that is intermediate between that of aftl and af leaves in the proximal region. Only the most distal tips are slightly expanded. Because the Af and Tl genes interact to affect almost all aspects of leaf and pinna form, they affect development at multiple levels of organization.Key words: acacia, afila, Fabaceae, leaf morphology, leaf anatomy, Pisum sativum.