A β‐galactosidase‐like gene is expressed during tobacco pollen development

Some viroids—single-stranded, non-coding, circular RNA parasites of plants—are not transmissible through pollen to seeds and to next generation. We analyzed the cause for the elimination of apple fruit crinkle viroid (AFCVd) and citrus bark cracking viroid (CBCVd) from male gametophyte cells of Nicotiana tabacum by RNA deep sequencing and molecular methods using infected and transformed tobacco pollen tissues at different developmental stages. AFCVd was not transferable from pollen to seeds in reciprocal pollinations, due to a complete viroid eradication during the last steps of pollen development and fertilization. In pollen, the viroid replication pathway proceeds with detectable replication intermediates, but is dramatically depressed in comparison to leaves. Specific and unspecific viroid degradation with some preference for (−) chains occurred in pollen, as detected by analysis of viroid-derived small RNAs, by quantification of viroid levels and by detection of viroid degradation products forming “comets” on Northern blots. The decrease of viroid levels during pollen development correlated with mRNA accumulation of several RNA-degrading factors, such as AGO5 nuclease, DICER-like and TUDOR S-like nuclease. In addition, the functional status of pollen, as a tissue with high ribosome content, could play a role during suppression of AFCVd replication involving transcription factors IIIA and ribosomal protein L5.

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Hormonome Dynamics During Microgametogenesis in Different Nicotiana Species

Frontiers in Plant Science ◽

10.3389/fpls.2021.735451 ◽

2021 ◽

Vol 12 ◽

Author(s):

Lenka Záveská Drábková ◽

Eva Pokorná ◽

Petre I. Dobrev ◽

Jana Kůrková ◽

Lenka Steinbachová ◽

...

Keyword(s):

Pollen Development ◽

Progressive Development ◽

Plant Groups ◽

Tobacco Pollen ◽

Pollen Ontogeny ◽

Pollen Growth ◽

Endogenous Phytohormones ◽

Nicotiana Langsdorffii ◽

First Time ◽

Derivatives Of

Plant microgametogenesis involves stages leading to the progressive development of unicellular microspores into mature pollen. Despite the active and continuing interest in the study of male reproductive development, little is still known about the hormonomics at each ontogenetic stage. In this work, we characterized the profiles and dynamics of phytohormones during the process of microgametogenesis in four Nicotiana species (Nicotiana tabacum, Nicotiana alata, Nicotiana langsdorffii, and Nicotiana mutabilis). Taking advantage of advanced HPLC-ESI-MS/MS, twenty to thirty endogenous hormone derivatives were identified throughout pollen ontogenesis, including cytokinins, auxins, ABA and its derivatives, jasmonates, and phenolic compounds. The spectra of endogenous phytohormones changed dynamically during tobacco pollen ontogeny, indicating their important role in pollen growth and development. The different dynamics in the accumulation of endogenous phytohormones during pollen ontogenesis between N. tabacum (section Nicotiana) and the other three species (section Alatae) reflects their different phylogenetic positions and origin within the genus Nicotiana. We demonstrated the involvement of certain phytohormone forms, such as cis-zeatin- and methylthiol-type CKs, some derivatives of abscisic acid, phenylacetic and benzoic acids, in pollen development for the first time here. Our results suggest that unequal levels of endogenous hormones and the presence of specific derivatives may be characteristic for pollen development in different phylogenetic plant groups. These results represent the currently most comprehensive study of plant hormones during the process of pollen development.

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Resolution of Channels in the Exine by Translocation of Colloidal Iron

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065808 ◽

1971 ◽

Vol 29 ◽

pp. 352-353

Author(s):

John R. Rowley

Keyword(s):

Phosphate Buffer ◽

Pollen Development ◽

Osmium Tetroxide ◽

Pollen Grains ◽

Deionized Water ◽

Colloidal Iron ◽

Fixed Material ◽

Epilobium Angustifolium ◽

Untreated Material ◽

Microspore Mitosis

The morphology of the exine of many pollen grains, at the time of flowering, is such that one can suppose that transport of substances through the exine occurred during pollen development. Holes or channels, microscopic to submicroscopic, are described for a large number of grains. An inner part of the exine of Epilobium angustifolium L. and E. montanum L., which may be referred to as the endexine, has irregularly shaped channels early in pollen development although by microspore mitosis there is no indication of such channeling in chemically fixed material. The nucleus in microspores used in the experiment reported here was in prophase of microspore mitosis and the endexine, while lamellated in untreated grains, did not contain irregularly shaped channels. Untreated material from the same part of the inflorescence as iron treated stamens was examined following fixation with 0.1M glutaraldehyde in cacodylate-HCl buffer at pH 6.9 (315 milliosmoles) for 24 hrs, 4% formaldehyde in phosphate buffer at pH 7.2 (1,300 milliosmoles) for 12 hrs, 1% glutaraldehyde mixed with 0.1% osmium tetroxide for 20 min, osmium tetroxide in deionized water for 2 hrs and 1% glutaraldehyde mixed with 4% formaldehyde in 0.1M cacodylate-HCl buffer at pH 6.9 for two hrs.

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Faculty Opinions recommendation of RiceAntherNet: a gene co-expression network for identifying anther and pollen development genes.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734933633.793555777 ◽

2019 ◽

Author(s):

Andy Pereira

Keyword(s):

Pollen Development

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Dynamic Changes in Activity and Distribution of Proteasome During Pollen Development of Pinus bungeana

CHINESE BULLETIN OF BOTANY ◽

10.3724/sp.j.1259.2012.00141 ◽

2012 ◽

Vol 47 (2) ◽

pp. 141-148

Author(s):

Jiang Liping ◽

Dong Xiaoling ◽

Li Xue ◽

Gao Yuan ◽

Sheng Xianyong

Keyword(s):

Pollen Development ◽

Dynamic Changes ◽

Pinus Bungeana

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OseIF3h Regulates Plant Growth and Pollen Development at Translational Level Presumably through Interaction with OsMTA2

Plants ◽

10.3390/plants10061101 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1101

Author(s):

Yuqing Huang ◽

Peng Zheng ◽

Xuejiao Liu ◽

Hao Chen ◽

Jumin Tu

Keyword(s):

Plant Growth ◽

Translation Initiation ◽

Pollen Development ◽

Messenger Rna ◽

Protein Biosynthesis ◽

Translation Initiation Factor ◽

Initiation Factor ◽

Sequencing Data ◽

Knock Out ◽

Translational Level

The initiation stage of protein biosynthesis is a sophisticated process tightly regulated by numerous initiation factors and their associated components. However, the mechanism underlying translation initiation has not been completely understood in rice. Here, we showed knock-out mutation of the rice eukaryotic translation initiation factor 3 subunit h (OseIF3h) resulted in plant growth retardation and seed-setting rate reduction as compared to the wild type. Further investigation demonstrated an interaction between OseIF3h and OsMTA2 (mRNA adenosine methylase 2), a rice homolog of METTL3 (methyltransferase-like 3) in mammals, which provided new insight into how N6-methyladenosine (m6A) modification of messenger RNA (mRNA) is engaged in the translation initiation process in monocot species. Moreover, the RIP-seq (RNA immunoprecipitation sequencing) data suggested that OseIF3h was involved in multiple biological processes, including photosynthesis, cellular metabolic process, precursor metabolites, and energy generation. Therefore, we infer that OseIF3h interacts with OsMTA2 to target a particular subset of genes at translational level, regulating plant growth and pollen development.

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