Oil accumulation in leaves directed by modification of fatty acid breakdown and lipid synthesis pathways
Oil accumulation in leaves directed by modification of fatty acid breakdown and lipid synthesis pathways
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DOI：
10.1111/j.1467-7652.2009.00435.x
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发表时间：
2009-09-01
影响因子：
13.8
通讯作者：
Graham, Ian A.
中科院分区：
文献类型：
--
作者：
Slocombe, Steve P.;Cornah, Jo;Graham, Ian A.
植物油以三酰甘油（TAG）的形式用于食品，工业原料和生物燃料制造。虽然TAG通常从油料作物物种的果实或种子中收获，但植物也可以在叶子和其他营养组织中积累少量TAG。在这里，我们表明，通过阻断脂肪酸分解，特别是在模式植物拟南芥的延长黑暗处理或叶片衰老期间，可以显着增加叶片TAG水平（10-20倍）。脂肪酸分解和二酰基甘油酰基转移酶1（DGAT 1）的双突变体的产生导致严重的营养生长表型，这表明在叶中的脂肪酸TAG的分配主要是通过这种酰基转移酶进行。LEC 2是一种参与贮藏产物积累的种子发育转录因子，在脂肪酸分解突变体COMATOSE（cts 2）衰老过程中异位表达。这导致TAG的种子油型物质在衰老组织中积累。我们的数据表明，再循环的膜脂肪酸可以通过在衰老组织中表达种子程序或通过阻止脂肪酸分解而重定向到TAG。这项工作提高了在生物质作物如芒草的营养组织中产生大量油的可能性。
P>Plant oils in the form of triacylglycerol (TAG) are used for food, industrial feedstock and biofuel manufacture. Although TAG is typically harvested from the fruit or seeds of oil crop species, plants can also accumulate small amounts of TAG in the leaves and other vegetative tissues. Here we show that leaf TAG levels can be increased significantly (10-20 fold) by blocking fatty acid breakdown, particularly during extended dark treatments or leaf senescence in the model plant Arabidopsis. Generation of a double mutant in fatty acid breakdown and diacylglycerol acyltransferase 1 (DGAT1) resulted in a severe vegetative growth phenotype suggesting that partitioning of fatty acids to TAG in leaves is carried out predominantly by this acyltransferase. LEC2, a seed development transcription factor involved in storage product accumulation, was ectopically expressed during senescence in the fatty acid breakdown mutant COMATOSE (cts2). This resulted in accumulation of seed oil type species of TAG in senescing tissue. Our data suggests that recycled membrane fatty acids can be re-directed to TAG by expressing the seed-programme in senescing tissue or by a block in fatty acid breakdown. This work raises the possibility of producing significant amounts of oil in vegetative tissues of biomass crops such as Miscanthus.