Preserving crop yield is critical for US soybean production and the global economy. Crop species have been selected for increased yield for thousands of years with individual lines selected for improved performance in unique environments, constraints not experienced by model species such as Arabidopsis. This selection likely resulted in novel stress adaptations, unique to crop species. Given that iron deficiency is a perennial problem in the soybean growing regions of the USA and phosphate deficiency looms as a limitation to global agricultural production, nutrient stress studies in crop species are critically important. In this study, we directly compared whole-genome expression responses of leaves and roots to iron (Fe) and phosphate (P_i) deficiency, representing a micronutrient and macronutrient, respectively. Conducting experiments side by side, we observed soybean responds to both nutrient deficiencies within 24 h. While soybean responds largely to –Fe deficiency, it responds strongly to P_i resupply. Though the timing of the responses was different, both nutrient stress signals used the same molecular pathways. Our study is the first to demonstrate the speed and diversity of the soybean stress response to multiple nutrient deficiencies. We also designed the study to examine gene expression changes in response to multiple stress events. We identified 865 and 3375 genes that either altered their direction of expression after a second stress exposure or were only differentially expressed after a second stress event. Understanding the molecular underpinnings of these responses in crop species could have major implications for improving stress tolerance and preserving yield.

中文翻译：

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大豆中微量营养素、常量营养素和多重胁迫暴露引起的动态基因表达变化。


保持作物产量对于美国大豆生产和全球经济至关重要。几千年来，人们一直在选择农作物品种以提高产量，并选择个别品系以在独特的环境中提高性能，而拟南芥等模式物种则不会遇到这种限制。这种选择可能导致作物物种特有的新的胁迫适应。鉴于缺铁是美国大豆种植区长期存在的问题，而缺磷已成为全球农业生产的限制，因此作物物种的营养胁迫研究至关重要。在这项研究中，我们直接比较了叶子和根对铁（Fe）和磷酸盐（P）缺乏（分别代表微量营养素和常量营养素）的全基因组表达反应。通过并行实验，我们观察到大豆在 24 小时内对两种营养缺乏做出反应。虽然大豆主要对缺铁反应，但它对磷补给反应强烈。尽管反应的时间不同，但这两种营养应激信号都使用相同的分子途径。我们的研究首次证明了大豆对多种营养缺乏的胁迫反应的速度和多样性。我们还设计了这项研究来检查基因表达变化对多种应激事件的反应。我们鉴定了 865 和 3375 个基因，这些基因要么在第二次应激暴露后改变了表达方向，要么仅在第二次应激事件后差异表达。了解作物物种这些反应的分子基础可能对提高胁迫耐受性和保持产量具有重大意义。