regulate the enzyme activity of ALDH2 in tolerant and sensitive varieties and in normal and submerged conditions. Future research. ⢠Which ALDH genes are the ...
Role of aldehyde dehydrogenase in submergence tolerance during germination in rice Berta Miro, Frederikson Entila, Abdelbagi M. Ismail Crop and Environmental Sciences Division, International Rice Research Institute, College , Los Banos, Philippines
Introduction
The roles of ALDH2a and ALDH2b in tolerance of submergence during germination
In soil conditions
Various traits seem to be associated with tolerance of flooding during germination in rice (AG, anaerobic germiantion); including:
Samples were collected every day between days 0 to 10.
ALDH2b
•High ROS amounts and CAT activity and lower peroxidase activity •Amylase activity •High alcoholic fermentation rates
Schematic of western blot and zymogram techniques
Results Metabolism under reduced oxygen conditions (submergence)
Aim To understand the mechanisms of tolerance of flooding during germination, particularly those related to the ethanol fermentation and their molecular characteristics.
Aldehyde dehydrogenase (ALDH) activity in native PAGE
IR42 DAS
•Two ALDH show activity in tolerant Khao Hlan On and only one in IR42
•These ALDH are common in both aerobic and submerged conditions during seed germination
Materials and Methods Varieties studied: TOLERANT SENSITIVE Khao Hlan On IR42 Mha Zhan (Red) FR13A Khaiyan
ALDH2b does not change between tolerant and sensitive varieties.
Conclusions
Aerobic conditions Khao Hlan On
In anaerobic conditions, the pI of ALDH2a decreases in tolerant varieties only.
•Changes in post-translational modifications may differentially regulate the enzyme activity of ALDH2 in tolerant and sensitive varieties and in normal and submerged conditions
Submerged conditions DAS
Future research Growth conditions and sampling:
• Which ALDH genes are the ones showing in-gel activity and what is the role of ALDH2 in submergence are still being investigated
In 0.1% agar conditions
Zymograms for ALDH using acetaldehyde as a substrate and NAD+ as a cofactor
Acknowledgements We’d like to thank Prof. Mikio Nakazono for providing the primary antibody against ALDH2.
