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Nonreciprocal complementation of KNOX gene function in land plants
Author(s) -
Frangedakis Eftychios,
SaintMarcoux Denis,
Moody Laura A.,
Rabbinowitsch Ester,
Langdale Jane A.
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14318
Subject(s) - physcomitrella patens , biology , bryophyte , complementation , fern , context (archaeology) , plant evolution , sporophyte , botany , moss , gene , multicellular organism , vascular plant , bryopsida , phylogenetic tree , evolutionary biology , genetics , mutant , ecology , genome , paleontology , species richness
Summary Class I KNOTTED ‐ LIKE HOMEOBOX ( KNOX ) proteins regulate development of the multicellular diploid sporophyte in both mosses and flowering plants; however, the morphological context in which they function differs. In order to determine how Class I KNOX function was modified as land plants evolved, phylogenetic analyses and cross‐species complementation assays were performed. Our data reveal that a duplication within the charophyte sister group to land plants led to distinct Class I and Class II KNOX gene families. Subsequently, Class I sequences diverged substantially in the nonvascular bryophyte groups (liverworts, mosses and hornworts), with moss sequences being most similar to those in vascular plants. Despite this similarity, moss mutants were not complemented by vascular plant KNOX genes. Conversely, the Arabidopsis brevipedicellus ( bp‐9 ) mutant was complemented by the Pp MKN 2 gene from the moss Physcomitrella patens . Lycophyte KNOX genes also complemented bp‐9 whereas fern genes only partially complemented the mutant. This lycophyte/fern distinction is mirrored in the phylogeny of KNOX ‐interacting BELL proteins, in that a gene duplication occurred after divergence of the two groups. Together, our results imply that the moss MKN 2 protein can function in a broader developmental context than vascular plant KNOX proteins, the narrower scope having evolved progressively as lycophytes, ferns and flowering plants diverged.