Arabidopsis thaliana'da indol-3-asetik asit (IAA), salisilik asit (SA) ve jasmonik asit (JA)' in yaprak senesensi üzerine etkisinin incelenmesi The investigation of the effect of indole-3-acetic acid (IAA), salicylic acid (SA) and jasmonic acid (JA) on leaf senescence in Arabidopsis thaliana