Isolation and functional analysis of MdNAS1, with functions in improved iron stress tolerance and abnormal flower in transgenic tobacco

Abstract

Nicotianamine is considered as the chelate substance in the transport of metal ions. In the present study, a new gene encoding NA synthase was isolated from Malus domestica (L.) Borkh and designated as MdNAS1. The expression levels of MdNAS1 were enriched in leaf, and phloem which were highly affected by Fe stress, indoleacetic acid (IAA) and abscisic acid (ABA) treatments in M. domestica seedlings. Subcellular localization research revealed that MdNAS1 was localized in cytoplasmic membrane. Overexpression of MdNAS1 in transgenic tobaccos increased the tolerance to Fe stress, but also contributes to higher chlorophyll, NA, Fe, Mn, Cu and Zn contents and abnormal flowers. Moreover, the MdNAS1-OE tobaccos had the increased expression levels of Fe uptake and transport related genes (NtFRO, NtIRT1, NtVIT, NtNRAMP1, and NtYSL).

Overexpression of a Malus baccata MYB Transcription Factor Gene MbMYB4 Increases Cold and Drought Tolerance in Arabidopsis thaliana

“…Then, RNA was used as the template to synthesize the first-strand cDNA with TransScript ® First-Strand cDNA Synthesis SuperMix (TransGen Biotech, Beijing, China) [53]. RNA and cDNA were assessed by 1.0% agarose gel electrophoresis [54]. The CDS region of MdMYB25 (NM_001293983.1, M. domestica) was used as the reference sequence, and primers (MbMYB4-F and MbMYB4-R, Supplementary Table S1) were designed with Primer 5.0 software.…”

“…After the primers were synthesized, they were used for the amplification of MbMYB4. The purified DNA was linked to the pEASY ® -T1 Cloning Kit (TransGen Biotech, Beijing, China) and sequenced [55,56].…”