Hsieh, Ming-Hsiun (謝明勳)
Associate Research Fellow
- Ph.D., Department of Biology, New York University, USA
- M.S., Department of Botany, National Taiwan University
- B.S., Department of Botany, National Taiwan University
- Plant molecular nutrition and signal transduction
Glutamine, the first organic nitrogen (N) derived from the primary N assimilation, is a major amino donor for the synthesis of amino acids, nucleotides, and other N-containing compounds in plants. In addition to its role in nutrition and metabolism, glutamine may also function as a signaling molecule in plants. Rice seedlings could effectively use glutamine as the sole N source (Fig. 1A). We used genomic approaches to identify genes that were rapidly regulated by glutamine, glutamate, and ammonium nitrate (Fig. 1B). Functional studies on these early glutamine, glutamate, and ammonium nitrate-responsive genes are underway.
Fig. 1 (A) Effects of glutamine on the growth of rice seedlings. (B) Venn diagram analysis of early Gln, Glu and NH4NO3 responsive genes in rice roots.
In addition, we designed a genetic screen to isolate mutants that could not grow well on medium containing glutamine as the sole N source in Arabidopsis (Fig. 2). These mutants may be defective in glutamine transport, allocation, metabolism or signaling. We are in the process of characterizing these mutants. Previously, we identified a novel type of ACT domain-containing protein family whose members contained ACT domain repeats (ACR). The ACT domain, an amino acid-binding domain named after bacterial aspartate kinase, chorismate mutase and TyrA (prephenate dehydrogenase), is a regulatory domain commonly found in amino acid metabolic enzymes. These ACR proteins may serve as amino acid sensors in plants. We have obtained several Arabidopsis acr mutants (Fig. 3), which will be used to study the functions of ACR proteins in plants.
Fig. 2 Phenotypes of the Arabidopsis dig1 (defective in glutamine1) mutant.
Fig. 3 Phenotypes of the Arabidopsis acr11 mutants.
Selected publication list
- Hsieh WY, Lin SC, Hsieh MH* (2018) Transformation of nad7 into the nuclear genome rescues the slow growth3 mutant in Arabidopsis. RNA Biol 15:1385-1391
- Hsieh PH, Kan CC, Wu HY, Yang HC, Hsieh MH* (2018) Early molecular events associated with nitrogen deficiency in rice seedling roots. Sci Rep 8: 12207
- Singh SK, Sung TY, Chung TY, Lin SY, Lin SC, Liao JC, Hsieh WY, Hsieh MH* (2018) ACR11 modulates levels of reactive oxygen species and salicylic acid-associated defense response in Arabidopsis. Sci Rep 8: 11851
- Hsieh WY, Liao JC, Wang HT, Hung TH, Tseng CC, Chung TY, MH Hsieh* (2017) The Arabidopsis thiamin deficient mutant pale green1 lacks thiamin monophosphate phosphatase of the vitamin B1 biosynthesis pathway. Plant J 91: 145-157
- Yang HC, Kan CC, Hung TH, Hsieh PH, Wang SY, Hsieh WY, Hsieh MH* (2017) Identification of early ammonium nitrate-responsive genes in rice roots. Sci Rep 7: 16885
- Kan CC, Chung TY, Wu HY, Juo YA, Hsieh MH* (2017) Exogenous glutamate rapidly induces the expression of genes involved in metabolism and defense responses in rice roots. BMC Genomics 18:186
- Liao JC, Hsieh WY, Tseng CC, Hsieh MH* (2016) Dysfunctional chloroplasts up-regulate the expression of mitochondrial genes in Arabidopsis seedlings. Photosynth Res 127:151–159.
- Kan CC, Chung TY, Juo YA, Hsieh MH* (2015) Glutamine rapidly induces the expression of key transcription factor genes involved in nitrogen and stress responses in rice roots. BMC Genomics 16: 731.
- Hsieh WY, Liao JC, Chang CY, Harrison T, Boucher C, Hsieh MH* (2015) The SLOW GROWTH3 pentatricopeptide repeat protein is required for the splicing of mitochondrial NADH dehydrogenase subunit7 intron 2 in Arabidopsis. Plant Physiol 168: 490-501.
- Hsieh WY, Sung TY, Wang HT, Hsieh MH* (2014) Functional evidence for the critical amino-terminal conserved domain and key amino acids of Arabidopsis 4-HYDROXY-3-METHYLBUT-2-ENYL DIPHOSPHATE REDUCTASE.Plant Physiol 166: 57-69.