Abstract:
Leafy sweet potato is rich in caffeoylquinic acids (CQAs), including monoCQAs and diCQAs, which are important for plant resistance to environmental stresses. However, knowledge about genes responsible for the accumulation of these CQAs in leafy sweet potato is limited. Previous studies have reported the involvement of glutathione S-transferase (GST) genes in the metabolism of plant secondary compounds like flavonols and anthocyanins; yet, the mechanism of CQA-related GST proteins is not well understood. In the present study, GST gene family was investigated in sweet potato by transcriptomic and comparative genomic analyses. A total of 51 genes were identified and confirmed as GST members of leafy sweet potato varieties EC16 and FS7-6. Among them, four GST members i.e., itb01g35330 (IbGSTTCHQD), itb09g30700 (IbGSTT), itb11g03220 (IbGSTU), and itb11g07110 (IbGSTL) belonging to TCHQD, Theta, Tau, and Lambda subfamilies were selected and investigated for their correlation with the accumulation of CQAs, as they exhibited secondary metabolism functions based on gene ontology classification. The genes were cloned from the leafy sweet potato varieties EC16 and FS7-6. Sequence alignment of the coding regions of these genes from the two varieties revealed slight mutations in the amino acid sequences. Besides, their expression was higher in the EC16 compared to the FS7-6 variety, which corresponds to the accumulated amounts of CQAs in both varieties. The amplified IbGST sequences from the EC16 variety were further transformed into Agrobacterium tumefaciens and subsequently introduced into Nicotiana benthamiana and Nicotiana tabacum for transient expression and transgenic transformation, respectively. Gene expression profiling in both transformation approaches revealed significant increases in IbGSTTCHQD and IbGSTT transcripts in transformed leaves, resulting in an enhanced accumulation of monoCQAs compared to the wild-types. However, no significant change was observed in the level of diCQAs. The IbGSTU and IbGSTL genes had no effect on the mono- and di-CQAs. Our findings suggested that IbGSTTCHQD and IbGSTT genes might be involved in the accumulation of monoCQAs in leafy sweet potato. In addition, these two genes responded positively to salinity, drought, and oxidative stresses. Their overexpression resulted in increased activities of GST, SOD, POD, CAT, and a lower content of MDA, indicating that IbGSTTCHQD and IbGSTT could act as stress regulators to strengthen the cells’ ability to scavenge ROS and improve leafy sweet potato plants resistance to abiotic stresses.
Speaker: Dr. Soviguidi Deka Reine Judesse
Affiliation: XTBG
Time: 4:30 PM, Tuesday, Oct. 18, 2022
Venue: ZOOM 会议平台 会议 ID：312 430 8960 会议密码 PWD：666666
ZOOM
会议 ID：312 430 8960
会议密码 PWD：666666
