Arabidopsis Cold Stress Tolerance Improvement via AthHOS۱-targeting HOS۱-amiRNA Approach

In this study, we examined the efficacy of the artificial microRNAs (amiRNAs) technology in targeting the HOS۱ gene for the enhancement of cold stress tolerance in Arabidopsis thaliana Ler-۰ ecotype. The impact of athHOS۱-amiRNA overexpression on the response of transgenic plants to cold stress was assessed using RT-qPCR in ۳-week-old seedlings of the T۳ generation. Additionally, the response of wild-type plants of the same age to cold stress (۴ºC) for various durations (۶, ۱۲, ۲۴, ۴۸, and ۹۶ hours) was also evaluated. Comparative analysis revealed that athHOS۱-amiRNA downregulated athHOS۱ in transgenic plants after prolonged exposure to low temperature (۴۸ h and ۹۶ h) (Pearson’s correlation coefficient of -۰.۴۰۷; P<۰.۰۵). Interestingly, while prolonged cold stress at ۹۶ h led to a significant upregulation of athHOS۱ in wild-type plants, the suppression of athHOS۱-amiRNA in transgenic plants disrupted the expected circadian rhythm of athHOS۱ by preventing its upregulation. Furthermore, T۳ plants that had been cold-acclimated exhibited a ۱۷% increase in freezing tolerance (-۱ to -۸°C) compared to wild-type plants, indicating the success of this approach in enhancing Arabidopsis tolerance to low temperatures, at least in the Ler-۰ ecotype. In order to gain a deeper understanding of the intricate dynamics of gene/protein networking during cold acclimation and its interaction with the athHOS۱-amiRNA approach, further characterization is required. This includes measuring the expression levels and half-life of athHOS۱-amiRNA and HOS۱ mRNA, as well as evaluating the protein level of HOS۱ and its direct targets, such as ICE۱, in different Arabidopsis ecotypes and at different time intervals of low temperature exposure.

کلیدواژه ها:

Arabidopsis thaliana ، Artificial miRNAs ، Cold acclimation ، Freezing tolerance.