Abstract
The present study aimed to evaluate the effects of different doses of gamma radiation on some physiological characters of onion genotypes and the expression of PAL gene in the best interaction of gamma irradiation dose and onion genotype treatment. To this aim, four onion genotypes (White-Qom, White-Neyshabour, Red-Ridge- Lump, and Red-Ray-Corrugated) irradiated at 0, 30, 60, 90, 120, and 150 Gy. After four months of storage (at 10-15 °C and 70% relative humidity), the effects of gamma rays on the dry matter (DM), protein content, phenylalanine ammonia lyase (PAL) and peroxidase (POD) were investigated. In addition, the expression of PAL gene in the best interaction of gamma irradiation dose and onion genotype treatment was assessed. The result indicated that POD activity was increased by most of the gamma irradiation levels; however, the protein content and PAL activity were decreased. Moreover, dry matter content was found to be highly genotype-dependent. A linear regression (R2= 0.82) between PAL activity and gamma irradiation levels, was observed. PAL activity decreased with increasing in gamma irradiation level, while the expression rate of PAL gene was not significantly changed between irradiated and non-irradiated control, indicating that the radiation might not have direct effects on the gene regulatory elements. These results suggest that gamma irradiation could reduce the PAL activity possibly by controlling abiotic stress sources such as fungal and bacterial stresses.
Highlights
Onion (Allium cepa L.) is one of the most important vegetable crops, a member of the Liliaceae family (Sabiu et al 2019)
The present study revealed the feasibility of gamma irradiation as an efficient tool for the management of onion storage
The result indicated that POD activity increased by most of the gamma irradiation levels, the protein content and phenylalanine ammonia lyase (PAL) activity decreased
Summary
Onion (Allium cepa L.) is one of the most important vegetable crops, a member of the Liliaceae family (Sabiu et al 2019). Jones & Mann (1964) proposed that Pakistan and Iran are the onion primary center of origin. Since ancient times, it is highly consumed in Iran (Fakhri et al 2018). Iran with 2,379,000 tons annually onion production, was among the top four producer countries (FAO 2017). Gamma irradiation have been widely used as a safe and effective method to increase storage time and shelf life in some crops such as onion (Nouri & Toofanian 2001), potato (Frazier et al 2006), pistachio (Akbari et al 2018), peach (Khan et al 2018), and pomegranate (Ashtari et al 2019)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
