Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
Pre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 opment. ovule and female gametophytic development, events leading to double fertilization, pollen germination and pollen tube and syngamy and triple fusion. Since basic embryological developmental details are already detailed in earlier literature, attention is focused only on recent data, particula Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 rly molecular data pertaining to these aspects. Special attention has been given to genetic control of anther tapetum, endothecium and anther dehiscenEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
ce, microsporogenesis, microgametogenesis, chalazal behaviour and function and female gametophytic development. The importance of cell cycle events inPre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 te • Ovule • Pollen tube • Syngamy • Tapetum • Triple fusion17.1IntroductionThe angiosperm flower typically has four whorls of lateral organs: sepals, petals, stamens and carpels. The outer w horls of sepals and petals are sterile and often do accessor}' functions in repro-K.v. Krishnamurthy (El)Cen Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 ter for Pharmaceutics. Pharmacognosy and Pharmacology. School of Life Sciences, Institute of Trans-Disciplinary Health Science and Technology (IHST),Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
Bangalore. Karnataka. Indiae-mail: kvkbdu@yahoo.co.induction. while the inner whorls of stamens and carpels, respectively, are the male and female repPre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 to one to many depending on the plant species. The stamens are free, fused to one another variously to form one to many bundles or attached to the petals or to the carpels. Each stamen typically has a stalk (filament) and an anther. the two being attached to each other by a connective. Staminal nec Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 taries may be present on the filaments or on the anthers of several species ofB. Bahadur Ct al. (eds.), plant Biology and Biotechnology: Volume I: PlaEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
in Diversity. Organization. Function and Improvement. DOI 10.1007/978-81-322-2286-6_l 7. o Springer India 2015409410K.v. Krishnamurthyunrelated familiPre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 gynoecium (or pistil). A typical gynoecium has a basal ovary bearing ơvu/eson special placental tissue (of various types), an apically situated style and a stigma at the tip of the style. There is great variation in the size, shape and number of style and stigma depending on the taxon.17.2Anther and Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 Male GametophyteThe anther is the actual male sexual region of the stamen. The term microsporangium is often used as a synonym of anther, but the forEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
mer term has a much wider connotation and also represents the homologue of the microspore-producing structures of other vascular groups, particularly Pre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 nd the microsporangium of other vascular plants, the male gametophytic organization and behaviour are significantly different. The gametophytic cycle in angiosperms shows extreme abbreviation in time and space, and the male gametophyte or pollen is often composed of just two cells, a vegetative cell Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 and a generative cell. Anther and pollen development is a critical phase in the life cycle of the angiosperms, and it involves precisely controlled cEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
ellular processes including cell division, cell differentiation and cell death due to diverse range of genes and their interaction (Sanders et al. 199Pre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 these sporangia coalesce to form two sacs or thecae in tetrasporangiate taxa and one in uni- and bi-sporangiate taxa, containing the pollen grains. The microsporangia are surrounded by an epidermal layer followed on the inside by the wall layers: the latter are made up of an endo-thecium. middle la Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 yers and a tapetum covering the sporangia! locule (Fig. 17.1).The anther primordium in transectional view is almost squarish to rectangular and is madEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
e of homogeneous parenchymatous tissue, covered by an epidermal layer. The archesporial tissue differentiates as a single or a group of two to a few aPre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 to the apex of the sporangium. The cells of (his (issue are distinct from the rest of (he anther (issue by (heir larger size and greater avidity for nuclear and cytoplasmic stains. The archesporial cells divide periclinally to form outer primary parietal cells and inner primary sporogenous cells. Bo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 th these may undergo further periclinal (and a few anticlinal) divisions to respectively form the wall layers and the sporogenous cells (Fig. 17.1): rEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
arely the latter directly function as sporogenous cells. Based on variations in anther wall development and the number of wall layers present, four tyPre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 in (he anther is the SPOROCYTELESS (SPLVNOZZLE (jVZZ) gene (Schiefthaler et al. 1999; Yang el al. 1999). In the spUnzz mutant, archesporial initiation occurs normally, but male sporocyte differentiation is halted and anther development fails to continue. The mutant genes of EXTRA SPO ROG ENOUS CELLS Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 (EXS)IEXCESS MICROSPOROCYTES i (EMSI) alter the number of archesporial cells. Two other genes SOMATIC EMBRYOGENESIS RECEPTORLIKE KINASEI (SERKI) andEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
SERK2 also have redundant functions during the earlier stages of anther development and. when mutated, result in more sporogenous cells (Albrecht et aPre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 ay be present in some taxa or may be totally absent as in cleistogamous flowers, aquatic plants and extreme saprophytes. The cells of17 Pre-fertilization: Reproductive Growth and Development411Fig. 17.1 (a-t). (a-n) Trachyspemium ammi. (o—1> Cuminum cyminum. Microsporangium (a, c. e. f. j, k. 111). Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 Outline diagrams for (b. d. f. h. j. I) and (nt. respectively, showing development of anther, (b. d. f. h. J. I. nt Enlargements of portions marked X.Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
XI. X2, X3, X4. X5and X(> in (a. c. e. g. i. k) and (in), respectively, (o. p) Endothecial cells showing thickenings (from whole mounts) Iq. r) laterPre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 othecium are often radially elongated and develop special banded thickening in the inner tangential walls and rarely on radial walls also when the sporangium fully matures (Fig. 17.1). The thickening material is not callose but an a-celhilose: in some it may be slightly lignified. Transcriptional ac Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 tivity is required for the differentiation of endothecium as is evident from the localization of poly(A)-RNA in rice microsporangia by in situ hybridiEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
zation using I 'HI poly(U) as a probe (Raghavan 2000). Just before meiosis poly(A)-RNA concentration decreases sharply in the epidermis and middle layPre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 some amount of poly(A)-RNA is retained in the endothecium. In rice and wheal anthers, the histone H3 gene also activates the endothelial differentiation, particularly in the wild-type and transgenic rice: however, the mechanism of this differentiation is not yet clear. The importance of endothecium Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 in anther dehiscence and the way in which the latter occurs are detailed on a subsequent page of this article.17.2.2TapetumAs already stated, (he inneEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
rmost wall layer of the microsporangium is the tapetum. To start with, it borders on the sporogenous cells, and because of its strategic position betwPre-fertilization: Reproductive Growth and DevelopmentK.v. KrishnamurthyAbstractThis chapter deals with details on anther and male gametophytic develo Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 he sporogenous tissue. it has been shown to have a dual origin (Fig. 17.2). The tapetai cells towards (he outer sector of (he microsporangium are derived from the primary parietal tissue, while those towards the centre of the anther are derived from the connective tissue. Although evidences of dual Ebook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2 originof tapetum are lost eventually and become a homogeneous layer in many taxa, there are differences in cell size, shape, number of cell layers, nuEbook Plant biology and biotechnology (Volume I: Plant diversity, organization, function and improvement): Part 2
clear size, shape and ploidy or time of differentiation. etc. between proximal and distal tapeta (Periasamy and Swamy 1966).Gọi ngay
Chat zalo
Facebook