Janda Tibor, Szalai Gabriella, Leskó Kornélia, Yordanova Rusina, Apostol Simona, Popova Losanka Petrova
Agricultural Research Institute of the Hungarian Academy of Sciences, H-2462, Martonvásár, POB 19, Hungary.
Phytochemistry. 2007 Jun;68(12):1674-82. doi: 10.1016/j.phytochem.2007.04.012. Epub 2007 May 29.
The interaction between light and temperature during the development of freezing tolerance was studied in winter wheat (Triticum aestivum L. var. Mv Emese). Ten-day-old plants were cold hardened at 5 degrees C for 12 days under normal (250 micromol m(-2)s(-1)) or low light (20 micromol m(-2)s(-1)) conditions. Some of the plants were kept at 20/18 degrees C for 12 days at high light intensity (500 micromol m(-2)s(-1)), which also increased the freezing tolerance of winter wheat. The freezing survival rate, the lipid composition, the antioxidant activity, and the salicylic acid content were investigated during frost hardening. The saturation level of hexadecanoic acid decreased not only in plants hardened at low temperature, but also, to a lesser extent, in plants kept under high light irradiation at normal growth temperature. The greatest induction of the enzymes glutathione reductase (EC 1.6.4.2.) and ascorbate peroxidase (EC 1.11.1.11.) occurred when the cold treatment was carried out in normal light, but high light intensity at normal, non-hardening temperature also increased the activity of these enzymes. The catalase (EC 1.11.1.6.) activity was also higher in plants grown at high light intensity than in the controls. The greatest level of induction in the activity of the guaiacol peroxidase (EC 1.11.1.7.) enzyme occurred under cold conditions with low light. The bound ortho-hydroxy-cinnamic acid increased by up to two orders of magnitude in plants that were cold hardened in normal light. Both high light intensity and low temperature hardening caused an increase in the free and bound salicylic acid content of the leaves. This increase was most pronounced in plants that were cold treated in normal light.
研究了冬小麦（Triticum aestivum L. var. Mv Emese）抗冻性发育过程中光与温度的相互作用。将10日龄的植株在正常光照（250 μmol m⁻²s⁻¹）或弱光（20 μmol m⁻²s⁻¹）条件下于5℃进行12天的低温锻炼。部分植株在高光强（500 μmol m⁻²s⁻¹）下于20/18℃保持12天，这也提高了冬小麦的抗冻性。在低温锻炼期间，对冻害存活率、脂质组成、抗氧化活性和水杨酸含量进行了研究。十六烷酸的饱和度不仅在低温锻炼的植株中降低，而且在正常生长温度下高光照射的植株中也有较小程度的降低。当在正常光照下进行冷处理时，谷胱甘肽还原酶（EC 1.6.4.2.）和抗坏血酸过氧化物酶（EC 1.11.1.11.）的诱导作用最强，但在正常非锻炼温度下的高光强也增加了这些酶的活性。过氧化氢酶（EC 1.11.1.6.）的活性在高光强下生长的植株中也高于对照。愈创木酚过氧化物酶（EC 1.11.1.7.）的活性在弱光低温条件下诱导程度最大。在正常光照下进行低温锻炼的植株中，结合态邻羟基肉桂酸增加了两个数量级。高光强和低温锻炼均导致叶片中游离态和结合态水杨酸含量增加。这种增加在正常光照下进行冷处理的植株中最为明显。
