Morphological Features of the Anther Development in Tomato Plants with Non-Specific Male Sterility

Abstract

The study was devoted to morphological and cytoembryological analysis of disorders in the anther and pollen development of transgenic tomato plants with a normal and abnormal phenotype, which is characterized by the impaired development of generative organs. Various abnormalities in the structural organization of anthers and microspores were revealed. Such abnormalities in microspores lead to the blocking of asymmetric cell division and, accordingly, the male gametophyte formation. Some of the non-degenerated microspores accumulate a large number of storage inclusions, forming sterile mononuclear pseudo-pollen, which is similar in size and appearance to fertile pollen grain (looks like pollen grain). It was discussed that the growth of tapetal cells in abnormal anthers by increasing the size and ploidy level of nuclei contributes to this process. It has been shown that in transgenic plants with a normal phenotype, individual disturbances are also observed in the development of both male and female gametophytes. The reason for the developmental arrest of some ovules was the death of endosperm at different stages of the globular embryo. At the same time, noticeable hypertrophy of endothelial cells performing a secretory function was observed. In the ovules of transgenic plants with abnormalities, the endothelium forms a pseudo-embryo instead of the embryo sac, stimulating the development of parthenocarpic fruits. The data obtained in this study can be useful for a better understanding of the genetic and molecular mechanisms of cytoplasmic male sterility and parthenocarpic fruit development in tomatoes.Biology 2020, 9, 32 2 of 17 enough, although quite a lot of research has been devoted to the cause of pollen sterility and the reasons for its manifestation in different plants [13].Previously, we performed a morphological, anatomical, and cytological study of anomalies in the flowers of transgenic tomatoes, which sometimes arise as a result of the genetic transformation procedure [14][15][16][17]. It was shown that the reason for the appearance of most anomalies in the flowers of transgenic tomatoes is a violation of the predetermined generative meristem growth. This leads to various kinds of disturbances in the formation of both gynoecium and androecium. It was found that pollen in most of the studied transgenic plants were sterile due to the arrest of asymmetric mitosis in microspores. Nevertheless, apparently, due to the hormonal deviations in cells around the embryo sac, so-called pseudo-embryonic tissue is formed in the unfertilized ovules from the inner epidermis of the integument. In turn, it stimulates the ovary to develop and form parthenocarpic fruits [18].The aim of this work was to identify the cytoembryological features of anthers and pollen development to establish morphological factors for pollen sterility at key stages of the androecium and gynoecium development in transgenic tomato plants with anomalies of generative organs, as well as in transgenic tomatoes without visible phenotypic anomalies, but ...

Aerially Applied Zinc Oxide Nanoparticle Affects Reproductive Components and Seed Quality in Fully Grown Bean Plants (Phaseolus vulgaris L.)

“…The aforementioned modifications could alter pollen fitness by reducing the cytoplasmic content and essential materials for exine and intine cell wall production. The literature declared that most of the abnormalities in pollen development are associated with an abnormal tapetal function ( Deng et al, 2018 ; Chaban et al, 2020 ). As expected, diverse factors such as abiotic stresses influence different developmental stages of pollen grain ( Barnabás et al, 2008 ; Smith and Zhao, 2016 ).…”

Identification of male-fertility gene AsaNRF1 and molecular marker development in cultivated garlic (Allium sativum L.)

“…Any abnormality in anther development may lead to pollen abortion and male sterility ( Qiu et al., 2018 ; Pu et al., 2019 ; Chaban et al., 2020 ; Li et al., 2020 ; Mondol et al., 2020 ; Ren et al., 2020 ; Kim and Kim, 2021 ; Shin et al., 2021 ; Zhang et al., 2021 ; Zheng et al., 2021 ; Deng et al., 2022 ; Qi et al., 2022 ). The male gametophyte in garlic flowers stops at the early stage of sexual cell development ( Koul and Gohil, 1970 ; Tchórzewska et al., 2015 ).…”

“…Plants with male sterility cannot produce fertile pollen, and this male sterility may be regulated by genes encoded in the nuclear (genic male sterility) or mitochondrial (cytoplasmic male sterility) genomes ( Garcia et al., 2019 ). Abnormalities in the formation of the pollen sac ( Chaban et al., 2020 ; Zheng et al., 2021 ), meiosis ( Qiu et al., 2018 ; Shin et al., 2021 ), callose ( Pu et al., 2019 ; Li et al., 2020 ), tapetum ( Mondol et al., 2020 ; Zhang et al., 2021 ), pollen wall ( Ren et al., 2020 ; Deng et al., 2022 ), and anther dehiscence ( Kim and Kim, 2021 ; Qi et al., 2022 ) during pollen development can lead to pollen abortion and a male-sterile phenotype. Tapetum and meiocytes are primarily affected in most sporophytic male-sterile mutants ( Guo and Liu, 2012 ).…”

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“…In this study, the sorghum anther developmental process exhibited both similarities and differences with other plant species. We have found that later stages of anther development are much alike across a broad range of different plant species while the early stages vary somewhat among different species (Sanders et al 1999 ; Zhang et al 2011 ; Ekici and Dane 2012 ; Wang et al 2012 ; Xu et al 2014 ; Tsou et al 2015 ; Browne et al 2018 ; Chaban et al 2020 ). The anther development in sorghum resembles mostly to those of maize anthers (Wang et al 2012 ; Moon et al 2013 ; Tsou et al 2015 ), followed by those in wheat and rice (Zhang et al 2011 ; Browne et al 2018 ).…”