Prunus persica Terpene Synthase PpTPS1 Interacts with PpABI5 to Enhance Salt Resistance in Transgenic Tomatoes

Ectopic expression of SaCTP3 from the hyperaccumulator Sedum alfredii in sorghum increases Cd accumulation for phytoextraction

The Cd tolerance protein SaCTP3, which responds to Cd stress, was identified in Sedum alfredii; however, how to improve the efficiency of phytoremediation of Cd-contaminated soil using the CTP gene remains unknown. In this study, the phytoremediation potential of SaCTP3 of Sedum alfredii was identified. In the yeast Cd-sensitive strain Δycf1 overexpressing SaCTP3, the accumulation of Cd was higher than that in the Δycf1 strain overexpressing an empty vector. Transgenic sorghum plants overexpression SaCTP3 were further constructed to verify the function of SaCTP3. Compared to wild-type plants, the SaCTP3-overexpressing lines exhibited higher Cd accumulation under 500 μM Cd conditions. The average Cd content inSaCTP3-overexpressing plants is more than four times higher than that of WT plants. This was accompanied by an enhanced ability to scavenge ROS, as evidenced by the significantly increased activities of peroxidase, catalase, and superoxide dismutase in response to Cd stress. Pot experiments further demonstrated that SaCTP3 overexpression resulted in improved soil Cd scavenging and photosynthetic abilities. After 20 days of growth, the average Cd content in the soil planted with SaCTP3-overexpressing sorghum decreased by 19.4%, while the residual Cd content in the soil planted with wild-type plants was only reduced by 5.4%. This study elucidated the role of SaCTP3 from S.alfredii, highlighting its potential utility in genetically modifying sorghum for the effective phytoremediation of Cd.

LcMYB106 suppresses monoterpene biosynthesis by negatively regulating LcTPS32 expression in Litsea cubeba

Litsea cubeba, the core species of the Lauraceae family, is valuable for the production of essential oils due to its high concentration of monoterpenes (90%). The key monoterpene synthase and metabolic regulatory network of monoterpene biosynthesis have provided new insights for improving essential oil content. However, there are few studies on the regulation mechanism of monoterpenes in L. cubeba. In this study, we investigated LcTPS32, a member of the TPS-b subfamily, and identified its function as an enzyme for the synthesis of monoterpenes, including geraniol, α-pinene, β-pinene, β-myrcene, linalool and eucalyptol. The quantitative real-time PCR analysis showed that LcTPS32 was highly expressed in the fruits of L. cubeba and contributed to the characteristic flavor of its essential oil. Overexpression of LcTPS32 resulted in a significant increase in the production of monoterpenes in L. cubeba by activating both the MVA and MEP pathways. Additionally, the study revealed that LcMYB106 played a negative regulatory role in monoterpenes biosynthesis by directly binding to the promoter of LcTPS32. Our study indicates that LcMYB106 could serve as a crucial target for metabolic engineering endeavors, aiming at enhancing the monoterpene biosynthesis in L. cubeba.

Genome-wide identification and expression analysis of SlRR genes in response to abiotic stress in tomato

The cytokinin two-component signal transduction system (TCS) is involved in many biological processes, including hormone signal transduction and plant growth regulation. Although cytokinin TCS has been well characterized in Arabidopsis thaliana, its role in tomato remains elusive. In this study, we characterized the diversity and function of response regulator (RR) genes, a critical component of TCS, in tomato. In total, we identified 31 RR genes in the tomato genome. These SlRR genes were classified into three subgroups (type-A, type-B and type-C). Various stress-responsive cis-elements were present in the tomato RR gene promoters. Their expression responses under pesticide treatment were evaluated by transcriptome analysis. Their expression under heat, cold, ABA, salinity and NaHCO₃ treatments was further investigated by qRT-PCR and complemented with the available transcription data under these treatments. Specifically, SlRR13 expression was significantly upregulated under salinity, drought, cold and pesticide stress and was downregulated under ABA treatment. SlRR23 expression was induced under salt treatment, while the transcription level of SlRR1 was increased under cold and decreased under salt stress. We also found that GATA transcription factors played a significant role in the regulation of SlRR genes. Based on our results, tomato SlRR genes are involved in responses to abiotic stress in tomato and could be implemented in molecular breeding approaches to increase resistance of tomato to environmental stresses.