Ben Abdallah Heithem, Mai Hans Jörg, Slatni Tarek, Fink-Straube Claudia, Abdelly Chedly, Bauer Petra
Institute of Botany, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
Laboratory of Extremophile Plant, Center of Biotechnology of Borj Cedria, Hammam-Lif, Tunisia.
Front Plant Sci. 2018 Oct 2;9:1383. doi: 10.3389/fpls.2018.01383. eCollection 2018.
Iron (Fe) is an essential element for plant growth and development. The cultivation of leguminous plants has generated strong interest because of their growth even on poor soils. Calcareous and saline soils with poor mineral availability are wide-spread in Tunisia. In an attempt to select better forage crops adapted to Tunisian soils, we characterized Fe deficiency responses of three different isolates of , an endemic Tunisian extremophile species growing in native stands in salt and calcareous soil conditions. is a non-model crop. The three isolates, named according to their habitats Karkar, Thelja, and Douiret, differed in the expression of Fe deficiency symptoms like morphology, leaf chlorosis with compromised leaf chlorophyll content and photosynthetic capacity and leaf metal contents. Across these parameters Thelja was found to be tolerant, while Karkar and Douiret were susceptible to Fe deficiency stress. The three physiological and molecular indicators of the iron deficiency response in roots, Fe reductase activity, growth medium acidification and induction of the homolog, indicated that all lines responded to -Fe, however, varied in the strength of the different responses. We conclude that the individual lines have distinct adaptation capacities to react to iron deficiency, presumably involving mechanisms of whole-plant iron homeostasis and internal metal distribution. The Fe deficiency tolerance of Thelja might be linked with adaptation to its natural habitat on calcareous soil.
铁（Fe）是植物生长发育所必需的元素。豆科植物的种植引发了人们浓厚的兴趣，因为它们即使在贫瘠的土壤上也能生长。在突尼斯，矿物质有效性差的石灰性和盐渍土壤分布广泛。为了筛选出更适合突尼斯土壤的优质饲料作物，我们对三种不同分离株的缺铁反应进行了表征，这三种分离株均为突尼斯特有的极端嗜盐菌，生长于盐碱土和石灰性土壤条件下的原生群落中。[该植物名称未给出，保留英文]是一种非模式作物。这三种分离株根据其栖息地分别命名为卡尔卡尔、特尔贾和杜里耶，它们在缺铁症状的表现上存在差异，如形态、叶片黄化（伴随着叶片叶绿素含量和光合能力受损）以及叶片金属含量等方面。在这些参数中，发现特尔贾具有耐受性，而卡尔卡尔和杜里耶对缺铁胁迫敏感。缺铁反应在根系中的三个生理和分子指标，即铁还原酶活性、生长培养基酸化以及[同源基因名称未给出，保留英文]同源物的诱导，表明所有品系对缺铁均有反应，然而，不同反应的强度有所不同。我们得出结论，各个品系对缺铁反应具有不同的适应能力，推测这涉及到全株铁稳态和内部金属分布的机制。特尔贾对缺铁的耐受性可能与其对石灰性土壤自然栖息地的适应性有关。
