Androsterone-induced molecular and physiological changes in maize seedlings in response to chilling stress.

The aim of study was to elucidate the influence of foliar sprays of androsterone in alleviating detrimental effects of chilling stress in maize seedlings. Eleven-days-old maize seedlings were treated with 10(-9) mol L(-1) androsterone and then transferred to a chamber with temperature of 10/7 °C (day/night) for 3 days. The stress injury was measured in terms of increase in electrolyte leakage, superoxide production and hydrogen peroxide level, and decrease in chlorophyll content. Androsterone application mitigated significantly the chilling-induced stress injury. Under chilling stress, the oxidative damage which was measured as malondialdehyde content was lesser in androsterone-applied seedlings that were associated with greater activities of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (POX), ascorbate peroxidase (APX) and glutathione reductase (GR). Moreover, SOD, POX and APX isozymes exhibited a strong correlation with changes in their activities. Androsterone application enhanced the level of antioxidant compounds like ascorbic acid, glutathione, proline and carotenoid as well as activities of antioxidant enzymes. Similarly, while androsterone treatment increased total antioxidant status, it reduced total oxidant status relative to chilling-stressed seedlings alone. Soluble protein profile was significantly changed by only chilling stress and chilling stress plus androsterone treatment, as well. According to these findings, it is possible to say that androsterone could be used to alleviate the damaging effects of chilling stress by improving antioxidative system in maize seedlings. This is the first study elucidating the effects of androsterone on resistance to chilling stress of plants.

Erdal S 《-》

Exogenous abscisic acid increases antioxidant enzymes and related gene expression in pepper (Capsicum annuum) leaves subjected to chilling stress.

Guo WL ，Chen RG ，Gong ZH ，Yin YX ，Ahmed SS ，He YM ... -  《Genetics and Molecular Research》

Involvement of anthocyanins in the resistance to chilling-induced oxidative stress in Saccharum officinarum L. leaves.

Whether anthocyanins elevate resistance to chilling-induced oxidative stress in Saccharum officinarum L. cv Badila seedlings is investigated. Plants with four fully expanded leaves were exposed to chilling stress (8 °C/4 °C, 11 h photoperiod) for 3 days and then transferred to rewarming condition (25 °C/20 °C, 11 h photoperiod) for another 2 days. At the end of the chilling period, H2O2 and superoxide radical (O2-) levels increased sharply and were near the same in the central (CL) and the final fully expanded leaves (FL). Moreover, the degree of chilling injury indicated by malonaldehyde concentration and percent of ion leakage also was near the same. Most of the tested parameters returned near to the control level after 2 days of rewarming. With further analyzing, we found that superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11), glutathione reductase (EC 1.6.4.2) activities increased much higher and catalase (EC 1.11.1.6) activity and ascorbate/dehydroascorbate ratio decreased much more in FL than CL in response to chilling. However, anthocyanins concentration coupling with glutathione/oxidized glutathione increased much higher in CL than FL under chilling stress. These finds suggest that anthocyanins at least partially compensate the relative deficiency of antioxidants in CL compared with FL. α,α-Diphenyl-β-picrylhydrazyl assays further confirmed this idea. The relationships between anthocyanins and antioxidants were analyzed and the possible mechanisms of the affection of anthocyanins on antioxidant metabolism were discussed.

Zhu JJ ，Li YR ，Liao JX 《-》

Modulating the antioxidant system by exogenous 2-(3,4-dichlorophenoxy) triethylamine in maize seedlings exposed to polyethylene glycol-simulated drought stress.

Xie T ，Gu W ，Zhang L ，Li L ，Qu D ，Li C ，Meng Y ，Li J ，Wei S ，Li W ... -  《PLoS One》

He-Ne laser preillumination improves the resistance of tall fescue (Festuca arundinacea Schreb.) seedlings to high saline conditions.

Gao LM ，Li YF ，Han R 《-》