Iron-superoxide dismutase and monodehydroascorbate reductase transcripts accumulate in response to internode rubbing...

Area of Science:

• Plant molecular biology
• Biochemistry
• Plant physiology

Background:

• Iron-superoxide dismutase (Fe-SOD) plays a crucial role in managing reactive oxygen species (ROS) in plants.
• Mechanical stimuli can induce physiological responses in plants, including oxidative stress.
• Understanding the early molecular events in plant responses to mechanical stress is vital for agricultural applications.

Purpose of the Study:

• To isolate and characterize the cDNA encoding iron-superoxide dismutase (Fe-SOD) from tomato (Lycopersicon esculentum).
• To investigate the induction of Fe-SOD and monodehydroascorbate reductase (MDHAR) gene expression in response to mechanical stimulation in tomato plants.

Main Methods:

• Rapid Amplification of cDNA Ends PCR (RACE-PCR) was used to isolate the Fe-SOD cDNA.
• Northern blot analysis was employed to quantify mRNA accumulation.
• Mechanical stimulation was applied to young growing internodes of tomato plants.

Main Results:

• A 746-bp Fe-SOD cDNA was isolated, predicting a 249-amino acid protein with potential chloroplast targeting.
• Mechanical stimulation (rubbing) of tomato internodes led to the rapid accumulation of both Fe-SOD and MDHAR mRNAs within 10 minutes.
• The results indicate a swift involvement of reactive oxygen species in the plant's response to mechanical stimuli.

Conclusions:

• Reactive oxygen species are rapidly generated and play an early role in the plant's response to mechanical stimulation.
• Fe-SOD and MDHAR are key components in the early oxidative burst triggered by mechanical stress in tomato plants.
• The findings provide insights into plant mechanosensing and stress response pathways.