Department of Biochemistry, Warsaw University of Life Sciences - SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland.
Plant Sci. 2010 Nov;179(5):543-8. doi: 10.1016/j.plantsci.2010.08.005. Epub 2010 Aug 13.
Aldehyde oxidase (AO, EC 1.2.3.1) is a molybdenohydroxylase that is considered to catalyze the final step in the synthesis of abscisic acid (ABA) and possibly of indole-3-acetic acid (IAA). Five AO activity bands were detected after native PAGE with indole-3-aldehyde (PsAO-α, -β, -γ, -δ, -κ) and three with abscisic aldehyde (PsAO-γ, -δ, -κ) in developing seeds of Pisum sativum. At early and mid-development, PsAO-α, -β, -γ and only PsAO-γ were observed, respectively, and their localization as well as the expression of PsAOs genes was almost exclusively restricted to the maternal fruit tissues, the seed coat and pericarp. Towards the end of rapid reserve synthesis, two additional isoforms (PsAO-δ, -κ) appeared in cotyledons, coinciding with a high transcript level of PsAO2. At this developmental stage, the activity level of PsAO-γ, was still considerable in the testa, and was higher than at earlier stages in the embryonic axis, which correlated with the PsAO3 transcript level. In mature dry seeds, AO activity and the expression of PsAOs became restricted to the embryonic tissues. The possible involvement of AO isoforms in ABA or IAA synthesis during pea seed development as well as the contribution of particular PsAO genes to the formation of the dimeric pea AO isoforms is discussed.
醛氧化酶（AO，EC 1.2.3.1）是一种钼羟化酶，被认为催化脱落酸（ABA）和吲哚-3-乙酸（IAA）合成的最后一步。在用吲哚-3-醛（PsAO-α、-β、-γ、-δ、-κ）进行天然 PAGE 后，在豌豆发育种子中检测到 5 个 AO 活性带，用脱落醛（PsAO-γ、-δ、-κ）检测到 3 个。在早期和中期发育过程中，分别观察到 PsAO-α、-β、-γ和仅 PsAO-γ，它们的定位以及 PsAOs 基因的表达几乎完全局限于母体果实组织、种皮和果皮。在快速储备合成的末期，在子叶中出现了另外两种同工酶（PsAO-δ、-κ），与 PsAO2 的高转录水平相吻合。在这个发育阶段，种皮中 PsAO-γ 的活性水平仍然相当高，并且比胚胎轴的早期阶段更高，这与 PsAO3 的转录水平相关。在成熟的干种子中，AO 活性和 PsAOs 的表达仅限于胚胎组织。讨论了 AO 同工酶在豌豆种子发育过程中参与 ABA 或 IAA 合成的可能性，以及特定 PsAO 基因对子囊 AO 同工酶二聚体形成的贡献。
