Rice tocopherol deficiency 1 encodes a homogentisate phytyltransferase essential for tocopherol biosynthesis and plant development in rice
RTD1 encodes a homogentisate phytyltransferase catalyzing a key step in rice tocopherol biosynthesis, confers cold tolerance and regulates rice development by affecting the accumulation of DELLA protein SLENDER RICE1.
Tocopherols are one of the most important lipid-soluble antioxidants having indispensable roles in living organisms. The physiological functions of tocopherols have been comprehensively characterized in animals and artificial membranes. However, genetic and molecular functions of tocopherols in plants are less understood. This study aimed to isolate a tocopherol-deficient mutant rtd1 in rice. The rtd1 mutant showed overall growth retardation throughout the growth period. Most of the agronomic traits were impaired in rtd1. Map-based cloning revealed that the RTD1 gene encoded a homogentisate phytyltransferase, a key enzyme catalyzing the committed step in tocopherol biosynthesis. RTD1 was preferentially expressed in green leafy tissues, and the protein was located in chloroplasts. Cold tolerance was found to be reduced in rtd1. The cold-related C-repeat-binding factor (CBF)/dehydration-responsive element-binding protein 1 (DREB1) genes were significantly upregulated in rtd1 under natural growth conditions. Moreover, rtd1 exhibited a reduced response to gibberellin (GA).The transcript and protein levels of DELLA protein-coding gene SLENDER RICE 1 (SLR1) in rice was increased in rtd1. However, the GA content was not changed, suggesting a transcriptional, not posttranslational, regulation of SLR1. These findings implied that tocopherols play important roles in regulating rice growth and development.
KeywordsRice Tocopherol Cold tolerance DELLA Homogentisate phytyltransferase
Dehydration-responsive element-binding protein 1
Green fluorescent protein
High-performance liquid chromatography
Polyunsaturated fatty acids
This work was supported by the National Natural Science Foundation of China (31401036), the Natural Science Foundation of Jiangsu Province, China (BK20161308), the Jiangsu Independent Innovation Project, China (CX(14)5005), and the Basal Research Fund of Jiangsu Academy of Agricultural Sciences, China (ZX(15)4015).
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
- Achard P, Gong F, Cheminant S, Alioua M, Hedden P, Genschik P (2008) The cold-inducible CBF1 factor-dependent signaling pathway modulates the accumulation of the growth-repressing DELLA proteins via its effect on gibberellin metabolism. Plant Cell 20:2117–2129CrossRefPubMedPubMedCentralGoogle Scholar
- Cossins AR (1994) Temperature adaptation of biological membranes. Portland, LondonGoogle Scholar
- Hirano K, Aya K, Hobo T, Sakakibara H, Kojima M, Shim RA, Hasegawa Y, Ueguchi-Tanaka M, Matsuoka M (2008) Comprehensive transcriptome analysis of phytohormone biosynthesis and signaling genes in microspore/pollen and tapetum of rice. Plant Cell Physiol 49:1429–1450CrossRefPubMedPubMedCentralGoogle Scholar
- Ikeda A, Ueguchi-Tanaka M, Sonoda Y, Kitano H, Koshioka M, Futsuhara Y, Matsuoka M, Yamaguchi J (2001) Slender rice, a constitutive gibberellin response mutant, is caused by a null mutation of the SLR1 gene, an ortholog of the height-regulating gene GAI/RGA/RHT/D8. Plant Cell 13:999–1010CrossRefPubMedPubMedCentralGoogle Scholar
- Kobayashi M, Yamaguchi I, Murofushi N, Ota Y, Takahashi N (2006) Fluctuation and localization of endogenous gibberellins in rice. Agri Biol Chem 52:1189–1194Google Scholar
- Liu Q, Kasuga M, Sakuma Y, Abe H, Miura S, Yamaguchi-Shinozaki K, Shinozaki K (1998) Two transcription factors, DREB1 and DREB2, with an EREBP/AP2 DNA binding domain separate two cellular signal transduction pathways in drought- and low-temperature-responsive gene expression, respectively, in Arabidopsis. Plant Cell 10:1391–1406CrossRefPubMedPubMedCentralGoogle Scholar
- Stockinger EJ, Gilmour SJ, Thomashow MF (1997) Arabidopsis thaliana CBF1 encodes an AP2 domain-containing transcriptional activator that binds to the C-Repeat/DRE, a cis-acting DNA regulatory element that stimulates transcription in response to low temperature and water deficit. Proc Natl Acad Sci USA 94:1035–1040CrossRefPubMedPubMedCentralGoogle Scholar
- Valentin HE, Lincoln K, Moshiri F, Jensen PK, Qi Q, Venkatesh TV, Karunanandaa B, Baszis SR, Norris SR, Savidge B, Gruys KJ, Last RL (2006) The Arabidopsis vitamin E pathway gene5-1 mutant reveals a critical role for phytol kinase in seed tocopherol biosynthesis. Plant Cell 18:212–224CrossRefPubMedPubMedCentralGoogle Scholar
- Vom DK, Hölzl G, Plohmann C, Eisenhut M, Abraham M, Weber AP, Hanson AD, Dörmann P (2015) Remobilization of phytol from chlorophyll degradation is essential for tocopherol synthesis and growth of Arabidopsis. Plant Cell 27:2846–2859Google Scholar
- Yoshida S, Forno DA, Cock JH (1976) Laboratory manual for physiological studies of rice. International Rice Research Institute, Los BañosGoogle Scholar
- Zhou S, Wang Y, Li W, Zhao Z, Ren Y, Wang Y, Gu S, Lin Q, Wang D, Jiang L, Su N, Zhang X, Liu L, Cheng Z, Lei C, Wang J, Guo X, Wu F, Ikehashi H, Wang H, Wan J (2011) Pollen semi-sterility1 encodes a kinesin-1-like protein important for male meiosis, anther dehiscence, and fertility in rice. Plant Cell 23:111–129CrossRefPubMedPubMedCentralGoogle Scholar