Iron (Fe) is an essential plant nutrient and its deficiency typically limits plant growth. Long non‐coding (lnc) RNAs are involved in adaptive responses to nutrient stress; however, it is not known whether they function in the regulation of the canonical Fe‐deficiency response. The expression of Malus domestica (apple) lncRNA MSTRG.85814 is induced by Fe deficiency, as identified by high‐throughput strand‐specific RNA‐seq analysis of an apple homograft system. MSTRG.85814 has a complex structure, with 13 predicted RNA sequence variants, four of which are upregulated in the roots of plants experiencing Fe deficiency. We found that one MSTRG.85814 splice variant (MSTRG.85814.11) positively modulated its cis target mRNA derived from the small auxin upregulated gene SAUR32 . This in turn promoted the expression of SAUR32 and caused an increase in the expression of a plasma membrane proton ATPase, AHA10 . Using a pH imaging technique, a significant decrease in the apoplastic pH was observed to occur in the root tips of MSTRG.85814.11 or SAUR32 ‐overexpressing apple plants. Thus MSTRG.85814.11 was shown to positively promote SAUR32 expression, which then activated proton extrusion involved in the Fe‐deficiency response. These results reveal a mechanism by which lncRNA promotes environmental Fe‐deficiency stress adaption.

中文翻译：

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较长的非编码苹果RNA MSTRG.85814.11充当SAUR32的转录增强子，并有助于铁缺乏反应。

铁（Fe）是植物必需的营养素，铁的缺乏通常会限制植物的生长。长非编码（lnc）RNA参与了对营养胁迫的适应性反应。但是，尚不清楚它们是否在规范的缺铁反应的调节中起作用。的表达海棠斯蒂卡（苹果）lncRNA MSTRG.85814为Fe缺乏引起的，所确定的同种苹果系统的高通量链特异性RNA-SEQ分析。MSTRG.85814具有复杂的结构，具有13个预测的RNA序列变体，其中四个在遇到铁缺乏的植物根部上调。我们发现一个MSTRG.85814剪接变体（MSTRG.85814.11）正调节其源自小生长素上调基因SAUR32的顺式靶mRNA。这继而促进了SAUR32的表达并引起质膜质子ATPase AHA10的表达增加。使用pH成像技术，观察到在MSTRG.85814.11或过表达SAUR32的苹果植物的根尖发生了质外体pH的显着降低。因此，MSTRG.85814.11被证明可以积极促进SAUR32的表达，然后激活质子挤出，参与铁缺乏反应。这些结果揭示了lncRNA促进环境Fe缺乏胁迫适应的机制。