Expression analysis of reciprocal grafted of near-isogenic soybean lines under iron stress

Iron stress response signaling between roots and shoots is not well understood in soybean. While studies have identified early responses to iron stress (as early as 30 minutes) the signaling pathway has not been well documented. In this study we used near-isogenic lines (Clark [Clk] and IsoClark [Iso]) to create four types of grafts (scion/roots), two homografts (Clk/Clk and Iso/Iso) and two heterografts (Clk/Iso and Iso/Clk). In hydroponics we subjected half the grafted seedlings to iron stress and collected leaf and root tissue after 30 and 120 minutes after iron stress; we extracted and sequenced RNA from the tissue samples. We identified differentially expressed genes and differences in expression patterns between grafting combinations. These results support the hypothesis that the physiological and molecular iron stress response is determined by the root genotype.

大豆根与茎之间的铁胁迫响应信号通路尚不明确。尽管已有研究确定了铁胁迫的早期响应（最早可在30分钟内观察到），但该信号通路尚未得到充分记录。在本研究中，我们利用近等基因系（Clark [Clk] 和 IsoClark [Iso]）构建了四种类型的嫁接（接穗/根系），包括两种同质嫁接（Clk/Clk 和 Iso/Iso）以及两种异质嫁接（Clk/Iso 和 Iso/Clk）。在无土栽培条件下，我们将一半的嫁接幼苗暴露于铁胁迫中，并在铁胁迫后30分钟和120分钟收集叶片和根系组织；从组织样本中提取并测序RNA。我们鉴定了差异表达基因以及嫁接组合间的表达模式差异。这些结果支持了以下假说：生理和分子层面的铁胁迫响应由根系基因型所决定。