In AraBidopsis, MPK3 (AT3G45640) , MPK4 (AT4G01370) , and MPK6 (AT2G43790) are the Best characterized memBers of the MAPK family and have also Been demonstrated to Be part of the ABA signal transduction pathway. MPK3 is activated By Both ABA and hydrogen peroxide in AraBidopsis seedlings, and MPK3 overexpression increases ABA sensitivity in ABA-induced postgermination arrest of growth, suggesting that the ABA signal is transmitted through MPK3 in this system.
