Park Seung-Hyeon, Chung Moon-Soo, Lee Sungbeom, Lee Kyeong-Hwan, Kim Cheol Soo
Department of Plant Biotechnology, Chonnam National University, Gwangju 61186, Republic of Korea.
Korea Atomic Energy Research Institute, Jeollabuk-do 56212, Republic of Korea.
Biochem Biophys Res Commun. 2017 Dec 16;494(3-4):499-503. doi: 10.1016/j.bbrc.2017.10.092. Epub 2017 Oct 21.
Proline (Pro) metabolism in plants is involved in various cellular processes mediated during abiotic stress. However, the Pro-regulatory mechanisms are unclear. We used a suppressor mutation technique to isolate novel genes involved in the regulation of Pro metabolism in Arabidopsis. Using atrzf1 as a parental plant for T-DNA tagging mutagenesis, we identified a suppressor mutant, termed proline content alterative 21 (pca21), that displayed reduced Pro contents compared with the atrzf1 under osmotic stress conditions. Genomic Thermal Asymmetric Interlaced (TAIL)-PCR revealed pca21 harbored an inserted T-DNA in the region of At2g36620 that encodes Ribosomal Protein L24A. In general, the pca21 mutant partially suppressed the insensitivity of atrzf1 to osmotic stress and abscisic acid during seed germination and early seedling stage. Additionally, the pca21 mutant had increased MDA content and lower expression of several Pro biosynthesis-related genes than the atrzf1 mutant during drought condition. These results suggest that pca21 acts as partial suppressor of atrzf1 in the osmotic stress response through the Pro-mediated pathway.
植物中的脯氨酸（Pro）代谢参与非生物胁迫介导的各种细胞过程。然而，脯氨酸的调控机制尚不清楚。我们使用抑制突变技术在拟南芥中分离参与脯氨酸代谢调控的新基因。以atrzf1作为T-DNA标签诱变的亲本植物，我们鉴定出一个抑制突变体，称为脯氨酸含量改变21（pca21），在渗透胁迫条件下，与atrzf1相比，其脯氨酸含量降低。基因组热不对称交错PCR（TAIL-PCR）显示pca21在编码核糖体蛋白L24A的At2g36620区域含有一个插入的T-DNA。一般来说，pca21突变体在种子萌发和幼苗早期部分抑制了atrzf1对渗透胁迫和脱落酸的不敏感性。此外，在干旱条件下，pca21突变体的丙二醛（MDA）含量高于atrzf1突变体，且几个脯氨酸生物合成相关基因的表达低于atrzf1突变体。这些结果表明，pca21通过脯氨酸介导的途径在渗透胁迫反应中作为atrzf1的部分抑制因子发挥作用。
