Pignocchi Cristina, Foyer Christine H
Crop Performance and Improvement Division, Rothamsted Research, Harpenden, AL5 2JQ, Hertfordshire, UK.
Curr Opin Plant Biol. 2003 Aug;6(4):379-89. doi: 10.1016/s1369-5266(03)00069-4.
The apoplast has crucial functions in plant biology. It comprises all the compartments beyond the plasmalemma, including the cell wall. As the reservoir of information on the biotic and abiotic environment surrounding the cell and a major conduit of information between cells, the apoplast has functions in stress perception and the subsequent appropriate control of growth and defence. The oxidative burst phenomenon, caused by environmental challenges and pathogen attack in particular, oxidises the apoplast. Ascorbic acid (AA), the major and probably the only antioxidant buffer in the apoplast, becomes oxidised in these conditions. The apoplastic enzyme ascorbate oxidase (AO) also regulates the reduction/oxidation (redox) state of the apoplastic ascorbate pool. We propose that a key function of the oxidative burst and of AO is to modify the apoplastic redox state in such a way as to modify receptor activity and signal transduction to regulate defence and growth.
质外体在植物生物学中具有关键作用。它包括质膜之外的所有区室，包括细胞壁。作为细胞周围生物和非生物环境信息的储存库以及细胞间信息的主要传导途径，质外体在胁迫感知以及随后对生长和防御的适当调控中发挥作用。由环境挑战尤其是病原体攻击引起的氧化爆发现象会氧化质外体。抗坏血酸（AA）是质外体中的主要且可能是唯一的抗氧化缓冲剂，在这些条件下会被氧化。质外体酶抗坏血酸氧化酶（AO）也调节质外体抗坏血酸池的还原/氧化（氧化还原）状态。我们提出，氧化爆发和AO的关键功能是以改变受体活性和信号转导的方式来改变质外体氧化还原状态，从而调节防御和生长。
