Microsporogenesis in angiosperms takes places within the anther. Microspores are surrounded by a layer of cells, the tapetum, which degenerates during the later stages of pollen development with cytological features characteristic of programmed cell death (PCD). We report herein that the expression of AtBI-1, which suppresses Bax-induced cell death, in the tapetum at the tetrad stage inhibits t...

During angiosperm microsporogenesis, callose serves as a temporary wall to separate microsporocytes and newly formed microspores in the tetrad. Abnormal callose deposition and dissolution can lead to degeneration of developing microspores. However, genes and their regulation in callose metabolism during microsporogenesis still remain largely unclear. Here, we demonstrated that the Arabidopsis (...

the study aimed to investigate the microsporogenesis, tapetum and pollen development in petunia hybrida juss.under control and air pollution condition. the connective shows a well-developed placentoid, giving thesporogenous tissue a crescent-shape. the sporogenous tissue of each of the four anther locules is surrounded bydimorphic tapetum. the outer (towards the epidermis) and inner (towards th...

Brachiaria humidicola (Poaceae), originally from Africa, is an economically important pasture plant in tropical South America. An accession of B. humidicola (H038) collected from the wild African savanna (Mbeya, Tanzania) showed irregular microsporogenesis. This meiotic behavior was consistent with an allopolyploid origin. Multivalent chromosome association at diakinesis gave tri- to octavalent...

The present study reports the chromosome number and meiotic behavior including microsporogenesis of Actaea kashmiriana J. Compton its relation with pollen fertility seed set. species showed a count 2n=4x=32 chromosomal irregularities such as chromatin stickiness, cytomixis, laggard formation, bridges, micronuclei polysporads. B-chromosomes were also observed in this species. Due to these irregu...

Developmental constraints have been proposed to interfere with natural selection in limiting the available set of potential adaptations. Whereas this concept has long been debated on theoretical grounds, it has been investigated empirically only in a few studies. In this article, we evaluate the importance of developmental constraints during microsporogenesis (male meiosis in plants), with an e...

The entire pollen life span is driven by polyamine (PA) homeostasis, achieved through fine regulation of their biosynthesis, oxidation, conjugation, compartmentalization, uptake, and release. The critical role of PAs, from microsporogenesis to pollen-pistil interaction during fertilization, is suggested by high and dynamic transcript levels of PA biosynthetic genes, as well as by the activities...