Musa Türker

Molecular and Physiological Changes in Maize (Zea mays) Induced by Exogenous NAA, ABA and MeJa during Cold Stress

Different concentrations of abscisic acid (ABA), naphthalene acetic acid (NAA) and methyl jasmonate (MeJa) were applied to maize (Zea mays) plants exposed to cold stress. ABA enhanced plant resistance against the damaging effects of freezing. ABA-treated plants produced some specific proteins when exposed to cold. Prominent changes were observed in the size and number of stomata with the application of ABA during cold stress. MeJa inhibited root growth, but increased root dry weight during cold acclimation. The chlorophyll content was lower at 100 µg ml-1 NAA and 50 µg ml-1 MeJa and higher in the residual applications when compared with that in the control plants. Carotenoid levels increased in all NAA and some ABA treatments, decreased however in MeJa treatment. Exogenous MeJa treatments increased endogenous trans-zeatin (t-Z) and indole-3-acetic acide (IAA) in contrast decreased ABA levels. Exogenous NAA also increased endogenous IAA, ABA and zeatin riboside (ZR) levels, while exogenous ABA decreased endogenous IAA and ZR levels.

Allelopathic potential of macrofungi on germinating maize (Zea mays L.) grain

The effect of methanol extracts of 10 macrofungi was evaluated on grain germination of maize ( Zea mays L.). Germination percentage, radicle and plumule length and the level of carbohydrates and fatty acids were measured. Fungal metabolites inhibited germination up to 90.96%, plumule (97.77%) and radicle (92.83%) development. Plumule and radicle lengths were stimulated 35.26 and 10.60% in some assays, respectively. The fungal metabolites decreased the glucose (97.60%), sucrose (90.34%), fructose (96.85%), maltose (95.64%), oleic acid (97.50%) and linoleic acid (98.25%) levels, whereas increasing levels of the glucose (165.14%), sucrose (166.53%), fructose (83.18%), maltose (124.73%), oleic acid (6975.00%) and linoleic acid (5233.33%) were detected in some assays. It is concluded that macrofungi metabolites have commonly inhibitory effects on physiological and morphological processes of germinating maize grain except for considerable increases in the some parameters investigated.