Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan.
Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research, Stadt Seeland, Gatersleben, 06466, Germany.
Plant Cell Physiol. 2022 Sep 15;63(9):1242-1252. doi: 10.1093/pcp/pcac099.
NGATHA-Like 1 (NGAL1) transcription factor has been identified as a gene regulated through AUG-stop-mediated boron (B)-dependent translation stall; however, its function in B response remains unknown. Here, we show that NGAL1 plays an important role in the maintenance of B transport under both low- and high-B conditions in Arabidopsis thaliana. NGAL1 mRNA is accumulated predominantly in shoots in response to B stress. Independent ngal1 mutants carrying transferred DNA (T-DNA) and Ds-transposon insertions exhibit reduced B concentrations in aerial tissues and produce shortened and reduced number of siliques when B supply is limited. Furthermore, the expression of B transporter genes including nodulin 26-like intrinsic protein 6; 1 (NIP6;1), NIP5;1, NIP7;1 and borate exporter 1 (BOR1) is significantly decreased in ngal1 mutants under low-B condition, suggesting that NGAL1 is required for the transcript accumulation of B transporter genes to facilitate B transport and distribution under B limitation. Under high-B condition, ngal1 mutants exhibit reduced growth and increased B concentration in their shoots. The accumulation of BOR4 mRNA, a B transporter required for B efflux to soil, is significantly reduced in roots of ngal1 plants under high-B condition, suggesting that NGAL1 is involved in the upregulation of BOR4 in response to excess B. Together, our results indicate that NGAL1 is involved in the transcriptional regulation of B transporter genes to facilitate B transport and distribution under both low- and high-B conditions.
NGAL1 样 1（NGAL1）转录因子已被鉴定为通过 AUG-终止介导的硼（B）依赖性翻译停顿调节的基因；然而，其在 B 反应中的功能仍然未知。在这里，我们表明 NGAL1 在拟南芥低 B 和高 B 条件下的 B 转运维持中发挥重要作用。NGAL1 mRNA 主要在受到 B 胁迫的地上组织中积累。携带转移 DNA（T-DNA）和 Ds-转座子插入的独立 ngal1 突变体在空气组织中的 B 浓度降低，并且当 B 供应有限时产生缩短和减少的蒴果数量。此外，在低 B 条件下，B 转运体基因包括类豆球蛋白 26 内在蛋白 6；1（NIP6；1）、NIP5；1、NIP7；1 和硼酸外排蛋白 1（BOR1）的表达在 ngal1 突变体中显著降低，表明 NGAL1 是 B 转运体基因转录积累所必需的，以促进 B 转运和分布在 B 限制下。在高 B 条件下，ngal1 突变体表现出生长减少和地上组织中 B 浓度增加。BOR4 mRNA 的积累，一种 B 转运体，需要 B 从土壤中流出，在高 B 条件下 ngal1 植物的根中显著降低，表明 NGAL1 参与了过量 B 反应中 BOR4 的上调。总之，我们的结果表明 NGAL1 参与 B 转运体基因的转录调控，以促进低 B 和高 B 条件下的 B 转运和分布。
