Glyphosate-induced Alternative Splicing in Genes of Tea Plant

Objective Gene transcription and response mechanism of a tea plant exposed to glyphosate by herbicide spray were studied.

Method Transcriptome sequencing was performed on the nationally renowned tea cultivar Shuchazao (Camellia sinensis) one day and 5 d after a spray of glyphosate at the rate of 2.50 kg ai·hm⁻² on the field. Alternative splicing (AS) as detected in the differentially expressed genes was used to determine the molecular response of the plants.

Result After the herbicide application, 16.51% AS was retained at the highest level in the introns, which was followed by 13.58% on the 3' end and 8.43% on the 5' end. The percentage of the unchanged in the exons was the least at 6.75%, while all the remainders at 54.73%. One day after the spraying, 1588 differential AS genes (DAGs), and 5 d, 1,768, were detected on the plants. Of them, 788 were found at both sampling times and all in the flavonoid biosynthesis or pyruvate metabolism pathway related to glyphosate stress. Significantly, the AS in CsSDH1, CsSDH2, CsPR, CsADH, CsHD-Zip, and CsMYB were positively observed with the qRT-PCR analysis showing highly agreeable results between the expressions and the transcriptomes of CsSDH1, CsSDH2, CsMYB, and the AS.

Conclusion Numerous DAGs appeared in the tea plants exposed to glyphosate. With the confirmation, study on the molecular mechanism of the stress response as well as means to alleviate the ill-effects on the growth, quality deterioration, and yield decline on tea at plantations due to the herbicide application are in order.