Institute of Agro-Biotechnology, IdAB-CSIC-Public University of Navarre-Government of Navarre, Campus de Arrosadía s/n, E-31006 Pamplona, Navarra, Spain.
J Plant Physiol. 2012 Sep 1;169(13):1253-60. doi: 10.1016/j.jplph.2012.04.019. Epub 2012 Jul 26.
Three main families of SODs in plants may be distinguished according to the metal in the active center: CuZnSODs, MnSOD, and FeSOD. CuZnSODs have two sub-families localized either in plant cell cytosol or in plastids, the MnSOD family is essentially restricted to mitochondria, and the FeSOD enzyme family has been typically localized into the plastid. Here, we describe, based on a phylogenetic tree and experimental data, the existence of two FeSOD sub-families: a plastidial localized sub-family that is universal to plants, and a cytosolic localized FeSOD sub-family observed in determinate-forming nodule legumes. Anti-cytosolic FeSOD (cyt_FeSOD) antibodies were employed, together with a novel antibody raised against plastidial FeSOD (p_FeSOD). Stress conditions, such as nitrate excess or drought, markedly increased cyt_FeSOD contents in soybean tissues. Also, cyt_FeSOD content and activity increased with age in both soybean and cowpea plants, while the cyt_CuZnSOD isozyme was predominant during early stages. p_FeSOD in leaves decreased with most of the stresses applied, but this isozyme markedly increased with abscisic acid in roots. The great differences observed for p_FeSOD and cyt_FeSOD contents in response to stress and aging in plant tissues reveal distinct functionality and confirm the existence of two immunologically differentiated FeSOD sub-families. The in-gel FeSOD activity patterns showed a good correlation to cyt_FeSOD contents but not to those of p_FeSOD. This indicates that cyt_FeSOD is the main active FeSOD in soybean and cowpea tissues. The diversity of functions associated with the complexity of FeSOD isoenzymes depending of the location is discussed.
根据活性中心的金属，可将植物中的三种主要 SOD 家族区分开来：CuZnSOD、MnSOD 和 FeSOD。CuZnSOD 有两个亚家族，分别定位于植物细胞质或质体中，MnSOD 家族主要局限于线粒体，FeSOD 酶家族通常定位于质体中。在这里，我们根据系统发生树和实验数据描述了两种 FeSOD 亚家族的存在：一种是普遍存在于植物中的质体定位亚家族，另一种是在形成不定根的豆科结瘤植物中观察到的细胞质定位 FeSOD 亚家族。使用抗细胞质 FeSOD（cyt_FeSOD）抗体和针对质体 FeSOD（p_FeSOD）的新型抗体。硝酸盐过量或干旱等胁迫条件会显著增加大豆组织中的 cyt_FeSOD 含量。此外，在大豆和豇豆植物中，cyt_FeSOD 含量和活性随年龄的增长而增加，而在早期阶段，cyt_CuZnSOD 同工酶占主导地位。叶片中的 p_FeSOD 随着施加的大部分胁迫而减少，但这种同工酶在根部会因脱落酸而显著增加。植物组织中 p_FeSOD 和 cyt_FeSOD 含量对胁迫和衰老的反应差异很大，这表明它们具有不同的功能，并证实了两种免疫分化的 FeSOD 亚家族的存在。凝胶中 FeSOD 活性模式与 cyt_FeSOD 含量有很好的相关性，但与 p_FeSOD 含量无关。这表明 cyt_FeSOD 是大豆和豇豆组织中主要的活性 FeSOD。还讨论了与 FeSOD 同工酶位置复杂性相关的功能多样性。
