Evolutionary features of microspore and pollen grain development in Cyperaceae.

Autor: Rocha DM; Laboratório de Citogenética e Diversidade Vegetal (LCDV), Universidade Estadual de Londrina (UEL), Londrina, PR, 86057-970, Brazil. danilomassuiarocha@gmail.com., Nogueira FM; Faculdade de Filosofia Ciências e Letras de Ribeirao Preto (FFCLRP), Universidade de São Paulo (USP), Ribeirão Preto, SP, 14040-901, Brazil., André T; Departamento de Botânica, Instituto de Ciências Biológicas, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, Brasília, DF, 70910-900, Brazil., de Araujo Mariath JE; Laboratório de Anatomia Vegetal - LAVeg, Instituto de Biociências, Departamento de Botânica, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, Porto Alegre, RS, 9500, Brazil., Vanzela ALL; Laboratório de Citogenética e Diversidade Vegetal (LCDV), Universidade Estadual de Londrina (UEL), Londrina, PR, 86057-970, Brazil.
Jazyk: angličtina
Zdroj: Plant reproduction [Plant Reprod] 2023 Dec; Vol. 36 (4), pp. 333-342. Date of Electronic Publication: 2023 Aug 02.
DOI: 10.1007/s00497-023-00477-4
Abstrakt: Key Message: Asymmetric meiosis leading to the release of pollen grains as pseudomonads is a synapomorphy in Cyperaceae, but differences in microspore development are relevant in the family's evolutionary history. Cyperaceae members present atypical microsporogenesis, in which one meiotic product is functional while the other three degenerate, culminating in pseudomonad pollen formation. Differences during development, such as pseudomonad shape and degenerative microspore positioning, are seen throughout the family, but no phylogenetic interpretation has been made regarding these variances thus far. In this study, we analyzed the early- and late-diverging sedge genera Hypolytrum and Eleocharis, respectively, while comparing them to data available in the literature and conducting an ancestral character reconstruction for pseudomonad traits. Light microscopy results show that pseudomonad development in Hypolytrum is homologous to several other sedge genera, presenting apical degenerative microspores. However, pseudomonads are round and centrally arranged in the anther locule in this case, which consists of a pleisiomorphic trait for the family. The basal positioning of degenerative microspores is restricted to Rhynchospora, consisting of an apomorphic trait for this genus. Despite these differences, ultrastructural analysis of Eleocharis pseudomonad revealed shared features with other genera studied, which include variations in chromatin condensation and cytoplasmic turnover in functional cells. These common features seem related to the different cellular fates seen during microspore development and further corroborate the synapomorphic status of pseudomonads in sedges.
(© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE