Acta Biologica Hungarica 2014-12-01 Regulation of auxin, abscisic acid and salicylic acid levels by ascorbate application under heat stress in sensitive and tolerant maize Burcu Seckin Dinler, Emel Demir, Yasemin Ozdener KompePMID 25475985 AbstractIn the present study, the effect of ascorbic acid (5 mM) on some physiological parameters and three hormones (auxin, abscisic acid, salicylic acid) was determined under heat stress (40 °C) in maize tolerant (MAY 69) and sensitive SHEMAL (SH) at 0 h, 4 h and 8 Heat stress reduced total chlorophyll content (CHL), relative water content (RWC) and stomatal conductance (gs) in SH but did not lead to changes in MAY 69 at 4 h and 8 However, pretreatment with ascorbic acid increased (CHL), (RWC) and (gs) in SH under heat stress while it reduced MDA content significantly in both We also observed that heat stress led to a reduction in SA level but increased ABA and IAA levels in SH, whereas it increased SA and IAA levels but did not change ABA level in MAY 69 at 4 Furthermore, in SH, ASC application under heat stress increased SA level and decreased IAA and ABA levels at 4 h, but it had no effect on SA and ABA at 8