Abstract

The qualitative composition and changes in the total fatty acid (FA) content in leaves of wild-type potato (Solanum tuberosum L., cv. Desnitsa) plants and plants transformed with the desA gene of Δ12-acyl-lipid desaturase from Synechocystis sp. PCC 6803 have been studied under cold hardening conditions (6 days at 5°С). During cold adaptation, plants of both types increase their cold resistance, but transformed plants significantly exceed control ones in relation to this parameter. Following cold hardening, the content of total etherified FA in leaves of control plants increases by almost 25% due to the decrease in the content of saturated FA and almost 30% increase in the content of polyunsaturated FA (PUFA); the growth of the PUFA content is provided mainly by linoleic (C_18:2) and linolenic (C_18:3) acids. Nonhardened leaves of transformed plants are characterized by the same FA content (especially C_18:3) as the leaves of hardened control plants. Due to this fact, increase in the total FA content in hardened transformants is not so significant as in the control; at the same time, the content of linoleic (C_18:2) acid increases by 30% (the calculated activity index for ∆12-desaturases also slightly increased). The growth of a hexadecatrienic (С_16:3) acid content in transformed plants probably results from a low-temperature activation of potato ω3-desaturases. The obtained data allow one to suppose that the higher resistance of transformed plants compared to control ones is connected with a constitutively increased PUFA content and determines more efficient cold hardening of such plants.

中文翻译：

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冷硬化过程中马铃薯叶片中脂肪酸组成和脂质含量的变化：Δ12-酰基脂质去饱和酶的作用

摘要

定性组成和在总脂肪酸中的改变野生型马铃薯叶（FA）含量（马铃薯L.，CV。Desnitsa）与转化的植物和植物DESA从Δ12酰基-脂质去饱和酶的基因集胞藻sp。已经在冷硬化条件下（在5°С下放置6天）研究了PCC 6803。在冷适应期间，两种类型的植物均会提高其抗寒性，但就此参数而言，转化的植物大大超过了对照植物。冷硬化后，由于饱和FA含量的减少和多不饱和FA（PUFA）含量的几乎30％的增加，对照植物叶片中总醚化FA的含量增加了近25％。PUFA含量的增长主要由亚油酸（C _18：2）和亚麻酸（C _18：3）酸提供。转化植物的未硬化叶子具有相同的FA含量（尤其是C _18：3））作为硬化对照植物的叶子。由于这个事实，硬化转化体中总FA含量的增加并不像对照中那样显着。同时，亚油酸（C _18：2）的含量增加了30％（计算出的Δ12-去饱和酶的活性指数也略有增加）。转化植物中十六碳六烯酸（С16 _：3）酸含量的增长可能是由于马铃薯ω3-去饱和酶的低温活化引起的。所获得的数据允许人们假设，与对照植物相比，转化植物的更高抗性与组成型增加的PUFA含量有关，并确定了这类植物的更有效的冷硬化。