Department of Crop Science, Chungnam National University, Yuseong-gu, Daejeon, Korea.
J Agric Food Chem. 2011 May 25;59(10):5412-7. doi: 10.1021/jf2009827. Epub 2011 Apr 26.
Phytoene synthase (PSY) and phytoene desaturase (PDS), which catalyze the first and second steps of the carotenoid biosynthetic pathway, respectively, are key enzymes for the accumulation of carotenoids in many plants. We isolated 2 partial cDNAs encoding PSY (AsPSY-1 and AsPSY-2) and a partial cDNA encoding PDS (AsPDS) from Allium sativum. They shared high sequence identity and conserved motifs with other orthologous genes. Quantitative real-time PCR analysis was used to determine the expression levels of AsPSY1, AsPSY2, and AsPDS in the bulbils, scapes, leaves, stems, bulbs, and roots of garlic. High-performance liquid chromatography demonstrated that carotenoids were not biosynthesized in the underground organs (roots and bulbs), but were very abundant in the photosynthetic organs (leaves) of A. sativum. A significantly higher amount of β-carotene (73.44 μg·g(-1)) was detected in the leaves of A. sativum than in the other organs.
类胡萝卜素生物合成途径的第一步和第二步分别由八氢番茄红素合酶 (PSY) 和八氢番茄红素脱氢酶 (PDS) 催化，它们是许多植物中类胡萝卜素积累的关键酶。我们从大蒜中分离出 2 个编码 PSY (AsPSY-1 和 AsPSY-2) 的部分 cDNA 和 1 个编码 PDS (AsPDS) 的部分 cDNA。它们与其他同源基因具有高度的序列同一性和保守基序。定量实时 PCR 分析用于确定大蒜鳞茎、花梗、叶片、茎、鳞茎和根中 AsPSY1、AsPSY2 和 AsPDS 的表达水平。高效液相色谱法表明，类胡萝卜素在地下器官（根和鳞茎）中没有生物合成，但在大蒜的光合器官（叶片）中非常丰富。在大蒜的叶片中检测到的β-胡萝卜素（73.44μg·g(-1))明显高于其他器官。
