Expression of sunflower cytoplasmic male sterility-associated open reading frame, orfH522 induces male sterility in transgenic tobacco plants

Abstract Background Cytoplasmic male sterility (CMS) is a trait associated with non-functional pollen or anthers, caused by the interaction between mitochondrial and nuclear genes. Findings A Tadukan-type CMS line (TAA) and a restorer line (TAR) were obtained by successive backcrossing between the Oryza sativa cultivars Tadukan (a cytoplasmic donor) and Taichung 65 (a recurrent pollen parent). Using Illumina HiSeq, we determined whole-genome sequences of the mitochondria of TAA and screened the mitochondrial genome for the presence of open reading frame (orf) genes specific to this genome. One of these orf genes, orf312, showed differential expression patterns in TAA and TAR anthers at the meiotic and mature stages, with transcript amounts in TAR being less than those in TAA. The orf312 gene is similar to the previously described orf288, a part of which is among the components comprising WA352, a chimeric CMS-associated gene of wild-abortive-type CMS. Conclusions The orf312 gene is a promising candidate for CMS-associated gene in TAA.

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Overexpression of the pitaya phosphoethanolamine N-methyltransferase gene (HpPEAMT) enhanced simulated drought stress in tobacco

Plant Cell Tissue and Organ Culture (PCTOC) ◽

10.1007/s11240-021-02040-3 ◽

2021 ◽

Author(s):

Ai-Hua Wang ◽

Lan Yang ◽

Xin-Zhuan Yao ◽

Xiao-Peng Wen

Keyword(s):

Drought Stress ◽

Stress Response ◽

Transgenic Plants ◽

Drought Tolerance ◽

Transgenic Tobacco ◽

Sequence Similarity ◽

Amino Acid Sequence Similarity ◽

Transgenic Tobacco Plants ◽

Wild Type ◽

Tobacco Plants

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.

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