外源诱导物对百里香植株再生过程中脂氧合酶活性的影响

以1/2 MS为基本培养基，分别用不同浓度梯度的蔗糖、NO3-/NH4+、丙氨酸、谷氨酸和丙酮酸处理百里香（Thymus vulgaris)再生植株30 d后，测定其对脂氧合酶(LOX)活性的影响。另外，培养百里香20、30和 40 d 后分别用茉莉酸甲酯、水杨酸和壳聚糖等外源因子对百里香进行处理，在不同的处理时间下测定LOX活性，探讨外源因素对增殖百里香中LOX活性的影响。结果表明，碳氮源调控30 d百里香，蔗糖浓度为4%、NO3-/NH4+比例为2∶1时最高；前体调控添加0.6 mmol·L-1苯丙氨酸和0.4 mmol·L-1谷氨酸诱导LOX活性达到最大值，丙酮酸对LOX酶活几乎无影响；20 d百里香经1.0 mmol·L-1 MeJA喷施诱导48 h后LOX活性为对照的655.4％，经150 mg·L-1 SA诱导12 h后LOX活性为对照的503.8％，经200 mg·L-1壳聚糖诱导24 h后LOX的活性为对照的429.1％。30 d百里香经0.5 mmol·L-1 MeJA诱导48 h后LOX的活性为对照的688.1％，经150 mg·L-1 SA诱导12 h后LOX的活性为对照的383.8％,经200 mg·L-1壳聚糖诱导24 h后LOX的活性为对照的360.8％。40 d百里香在外源处理因素作用下对LOX活性作用不明显。可见，在不同时期用不同处理因素对百里香再生植株进行处理能显著调节LOX的活性。

Effects of different factors on fatty acid oxidation activity of thyme

Plantlets of thyme were cultured on the 1/2 MS medium that containing surcose with different concentrations, NO3-/NH4+, phenylalanine, glutamic acid and pyruvic acid. The LOX activity of thyme was tested after 30 d. Furthermore, the plantlets were induced for 0～120 h by MeJA, SA and chitosan at different culture for 20 d, 30 d and 40 d, and LOX activity was tested. The results showed that the highest LOX activity was obtained when the plantlets of thyme were cultured on the 1/2 MS medium with 4% sugar and 2∶1 NO3-/NH4+ ratio for 30 d. The LOX activities were increased respectively when adding 0.6 mmol·L-1 precursor regulation L phenylalanine, 0.4 mmol·L-1 glutamic acid. The LOX activities of plantlets cultured for 20 d were 655.4％, 503.8％ and 429.1％ more than control by adding 1.0 mmol·L-1 MeJA,150 mg·L-1 SA, and 200 mg·L-1 chitosan. The LOX activities of plantlets cultured for 30 d were increased to 688.1％, 383.8％ and 383.3％ when adding 0.5 mmol·L-1 MeJA, 150 mg·L-1 SA, and 200 mg·L-1 chitosan, respectively. The LOX activities of plantlets cultured for 40 d did not change. Therefore, the LOX activity was affected by adding different inducer at different time.