Alkarawi Hassan Hadi, Zotz Gerhard
Functional Ecology Group, Institute of Biology and Environmental Sciences, University of Oldenburg, Box 2503, 26111 Oldenburg, Germany Foundation of Technical Education, Al-Musaib Technical College, Babylon, Iraq.
Functional Ecology Group, Institute of Biology and Environmental Sciences, University of Oldenburg, Box 2503, 26111 Oldenburg, Germany
AoB Plants. 2014 Aug 13;6:plu048. doi: 10.1093/aobpla/plu048.
Phytic acid is the major storage compound for phosphorus (P) in plants. While accounting for up to 90 % in many seeds, usually only <10 % of total P is found in phytic acid in green leaves. This study follows up on the findings of a recent review of the occurrence of phytic acid in green leaves which revealed that (i) the current knowledge of phytic acid in leaves is mostly based on data from (fertilized) crop plants and (ii) the proportion of total P in phytic acid seems to decrease with improved P status in leaves in contrast to an increase in seeds and fruit. We studied five species of wild herbaceous plants in the field and under controlled conditions. Foliar P concentrations were much lower than those of the crops of earlier studies, but the proportion of P in phytic acid was similar, with little variation during the observation period. Both the field data and the experimental data showed a statistically indistinguishable negative correlation of phytic acid-P/total P and total P. In contrast to our expectation, this negative relationship was not related to differences in relative growth rates. We conclude that (i) our data of phytic acid concentrations in leaves of wild plants are in line with earlier observations on crops, and (ii) the trend towards lower proportions of phytic acid-P with increasing P status is probably a general phenomenon. Currently lacking a convincing explanation for the second observation, the role of phytic acid in foliar P metabolism is still unclear.
植酸是植物中磷（P）的主要储存化合物。在许多种子中，植酸含量高达90%，而在绿叶中，通常只有不到10%的总磷存在于植酸中。本研究跟踪了最近一篇关于绿叶中植酸存在情况综述的研究结果，该综述表明：（i）目前关于叶片中植酸的知识大多基于（施肥的）农作物的数据；（ii）与种子和果实中植酸占总磷的比例增加相反，叶片中植酸占总磷的比例似乎会随着磷含量的提高而降低。我们在田间和受控条件下研究了五种野生草本植物。叶片中的磷浓度远低于早期研究中的农作物，但植酸中磷的比例相似，在观察期内变化很小。田间数据和实验数据均显示，植酸磷/总磷与总磷之间存在统计学上无显著差异的负相关。与我们的预期相反，这种负相关关系与相对生长率的差异无关。我们得出以下结论：（i）我们关于野生植物叶片中植酸浓度的数据与早期对农作物的观察结果一致；（ii）随着磷含量的增加，植酸磷比例降低的趋势可能是一种普遍现象。目前对于第二个观察结果缺乏令人信服的解释，植酸在叶片磷代谢中的作用仍不清楚。
