bims-pisump 2018-07-01 papers

Issue of 2018–07–01
two papers selected by
Vera S. Bogdanova, ИЦиГ СО РАН

Biochem Biophys Res Commun. 2018 Jun 21. pii: S0006-291X(18)31420-7. [Epub ahead of print]

The zinc-finger transcription factor BcMF20 and its orthologs in Cruciferae which are required for pollen development.

Ying-Yan Han, Hui-Yan Zhou, Li-Ai Xu, Xue-Ying Liu, Shuang-Xi Fan, Jia-Shu Cao.

Brassica campestris Male Fertility 20 (BcMF20) is a typical zinc-finger transcription factor that was previously isolated from flower buds of Chinese cabbage (Brassica campestris ssp. chinensis). By applying expression pattern analysis, it can be known that BcMF20 was specifically and strongly expressed in tapetum and pollen, beginning from the uninucleate stage, and was maintained during the mature-pollen stage. As BcMF20 was highly conserved in Cruciferae, it can be indicated that this zinc-finger transcription factor is important during the growth of Cruciferae. In this study, 12 C2H2-type zinc-finger TFs which shared high homology with BcMF20 were found from NCBI via BLAST. A new molecular phylogenetic tree was constructed by the comparison between BcMF20 and these 12 C2H2-type zinc-finger TFs with NJ method. By analyzing this phylogenetic tree, the evolution of BcMF20 was discussed. Then, antisense RNA technology was applied in the transgenesis of Arabidopsis thaliana to get the deletion mutants of BcMF20, so that its function during the pollen development can be identified. The results showed: BcMF20 are in the same clade with three genes from Arabidopsis. The inhibition of BcMF20 expression led to smaller amounts of and lower rate in germination of pollen and lower rate in fruit setting in certain transgenetic plants. This also led to the complete collapse of pollen grains. By SEM and TEM, pollen morphology and anther development processes were observed. In the middle uninucleate microspore stage, a relatively thin or even no primexine was formed in microspores. This may result in the malformation of the pollen wall and finally cause the deformity of pollens. Above all, it can be indicated that BcMF20 may act as a part of regulation mechanisms of TAZ1 and MS1. Together they play a role in a genetic pathway in the tapetum to act on proliferation of tapetal cells and keep the normal development of pollens.

Keywords: Brassica campestris ssp. chinensis; Pollen wall development; TFs; Tapetum; Vacuole

DOI: https://doi.org/10.1016/j.bbrc.2018.06.108

J Plant Physiol. 2018 Jun 13. pii: S0176-1617(18)30292-X. [Epub ahead of print]228 166-177

Epigenetic control of defense genes following MeJA-induced priming in rice (O. sativa).

Bertini Laura, Proietti Silvia, Focaracci Francesca, Sabatini Benedetta, Caruso Carla.

In plant defense, priming is a physiological process by which a plant prepares to more quickly or aggressively respond to a future biotic or abiotic stress. This unique physiological state can be induced by beneficial microbes or by treatment with natural or synthetic compounds. Priming has been described copiously, mainly in dicots, but the study on the molecular mechanisms regulating the phenomenon is still at its infancy. A fascinating possibility is that epigenetic changes may be the main actors on priming establishment. A more accessible chromatin structure, due to DNA methylation and/or histone modifications, could facilitate a quicker and more potent gene response to a subsequent attack. Here, we investigated the impact of methyl jasmonate (MeJA)-induced priming on the response efficacy to mechanical wounding of a monocot (Oryza sativa). In particular, we showed that MeJA primes plants for increased expression of defense-related genes, such as OsBBPI and OsPOX, upon wounding. Finally, we provided evidence that MeJA modulates histone modifications in the promoter region of OsBBPI, as well as changes at genome-wide DNA methylation level. Together these studies corroborate the importance of priming in strengthening plant defense and support the growing evidence that epigenetic regulation plays a pivotal role in priming onset.

Keywords: ChIP assay; Epigenetics; Immunolabeling; Methylation specific PCR; Priming; Rice

DOI: https://doi.org/10.1016/j.jplph.2018.06.007