Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences (SGGW), Nowoursynowska 166 St., 02-787 Warsaw, Poland.
Department of Botany, Institute of Biology, Warsaw University of Life Sciences (SGGW), Nowoursynowska 166 St., 02-787 Warsaw, Poland.
Int J Mol Sci. 2021 Apr 28;22(9):4656. doi: 10.3390/ijms22094656.
According to current opinion, the first step of benzoxazinoids (BXs) synthesis, that is, the conversion of indole-3-glycerol phosphate to indole, occurs exclusively in the photosynthesising parts of plants. However, the results of our previous work and some other studies suggest that this process may also occur in the roots. In this study, we provide evidence that the first step of BXs synthesis does indeed occur in the roots of rye seedlings. We detected transcripts, BX1 enzyme, and six BXs (2-hydroxy-1,4-benzoxazin-3-one, 2,4-dihydroxy-1,4-benzoxazin-3-one, (2)-2--β-d-glucopyranosyl-4-hydroxy-(2)-1,4-benzoxazin-3(4)-one glucoside, 2,4-dihydroxy- 7-methoxy-1,4-benzoxazin-3-one, 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one glucoside, and 6-methoxy-2-benzoxazolinone) in the roots developed from seeds deprived of the coleoptile at 2 days after sowing (i.e., roots without contact with aerial parts). In roots regenerated in vitro, both transcripts and BX1 enzyme were detected at a low but still measurable levels. Thus, BXs are able to be synthesised in both the roots and above-ground parts of rye plants.
根据目前的观点，苯并恶嗪类（BXs）合成的第一步，即色氨酸-3-甘油磷酸转化为吲哚，仅发生在植物的光合作用部分。然而，我们之前的工作和其他一些研究的结果表明，这个过程也可能发生在根部。在这项研究中，我们提供了证据表明 BXs 合成的第一步确实发生在黑麦幼苗的根部。我们在种子萌发后 2 天（即与地上部分没有接触的根）中检测到了 转录本、BX1 酶和六种 BXs（2-羟基-1,4-苯并恶嗪-3-酮、2,4-二羟基-1,4-苯并恶嗪-3-酮、（2）-2--β-d-吡喃葡萄糖基-4-羟基-（2）-1,4-苯并恶嗪-3(4)-one 葡萄糖苷、2,4-二羟基-7-甲氧基-1,4-苯并恶嗪-3-酮、2,4-二羟基-7-甲氧基-1,4-苯并恶嗪-3-酮葡萄糖苷和 6-甲氧基-2-苯并恶唑啉酮）。在离体再生的根中，虽然转录本和 BX1 酶的水平较低，但仍可检测到。因此，BXs 能够在黑麦植物的根和地上部分中合成。
