Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, School of Tropical Crops, Hainan University, Haikou, 570228, China.
Planta. 2021 Nov 6;254(6):115. doi: 10.1007/s00425-021-03769-z.
The banana development was inhibited under the long-term magnesium deficiency (MD) stress, resulting in the leaf chlorosis. MYB108 and WRKY75 are involved in regulating the growth and development of banana leaves and roots under long-term MD. Magnesium deficiency (MD) causes plant growth inhibition, ageing acceleration, yield reduction and quality decline of banana (Musa paradisiaca AA), but the molecular regulatory mechanisms underlying the changes in response to long-term MD conditions remain unknown. In this study, a long-term MD experiment was performed with banana seedlings at the four-leaf stage. Compared to those in the control group, the growth of leaves and roots of seedlings in the long-term MD treatment experimental groups was inhibited, and the Mg content and chlorophyll contents were decreased. Leaves and roots of seedlings from the control and experimental groups were subsequently collected for RNA sequencing to identify the genes that respond to long-term MD. More than 50 million reads were identified from each sample, resulting in the detection of 3500 and 948 differentially expressed genes (DEGs) in the leaves and roots, respectively. MYB and WRKY transcription factors (TFs) involved in plant stress responses were selected for further analysis, and 102 MYB and 149 WRKY TFs were differentially expressed. Furthermore, two highly differentially expressed candidate genes, MYB108 and WRKY75, were functionally analyzed using Arabidopsis mutants grown under long-term MD conditions. The results showed that the density of root hairs on the wild type (WT) was than that on the myb108 and wrky75 mutants under MD, implying that the mutants were more sensitive to MD than the WT. This research broadens our understanding the underlying molecular mechanism of banana seedlings adapted to the long-term MD condition.
长期镁缺乏（MD）胁迫抑制香蕉发育，导致叶片黄化。MYB108 和 WRKY75 参与调节长期 MD 下香蕉叶片和根系的生长发育。镁缺乏（MD）会抑制植物生长、加速衰老、降低香蕉（Musa paradisiaca AA）产量和降低品质，但植物对长期 MD 条件变化的响应的分子调控机制尚不清楚。本研究以四叶期香蕉幼苗为材料进行长期 MD 实验。与对照组相比，长期 MD 处理实验组幼苗的叶片和根系生长受到抑制，Mg 含量和叶绿素含量降低。随后收集对照组和实验组幼苗的叶片和根系进行 RNA 测序，以鉴定对长期 MD 条件有响应的基因。从每个样本中鉴定出超过 5000 万条reads，分别在叶片和根系中检测到 3500 个和 948 个差异表达基因（DEGs）。选择参与植物应激反应的 MYB 和 WRKY 转录因子（TFs）进行进一步分析，发现 102 个 MYB 和 149 个 WRKY TFs 差异表达。此外，利用在长期 MD 条件下生长的拟南芥突变体对两个高度差异表达的候选基因 MYB108 和 WRKY75 进行功能分析。结果表明，在 MD 条件下，野生型（WT）的根毛密度大于 myb108 和 wrky75 突变体，这意味着突变体对 MD 比 WT 更敏感。这项研究拓宽了我们对香蕉幼苗适应长期 MD 条件的潜在分子机制的理解。
