Ji-Hong Liu
Professor, College of Horticulture and Forestry Sciences, Huazhong Agricultural University
Summary of my work
My research interest relates to the exploration and utilization of citrus germplasm with elite attributes, with the major focus on the following research areas, elucidation of physiological and molecular mechanisms underlying stress tolerance of elite germplasms, cloning and functional characterization of key genes involved in stress tolerance, and production of stress-resistant novel germplasms by means of genetic transformation. So far, we have cloned and characterized seven stress-responsive genes, and have inexplicitly illustrated the mode of action of some genes to gain new insight into the stress signaling pathway. We also generated transgenic sweet orange with enhanced resistance to citrus canker disease and transgenic trifoliate orange with improved salt tolerance. At present the transgenic plants are under scrupulous evaluation for their potential application.
Impacts in China
Citrus is one of the most important fruits in China. However, development of citrus industry is impeded by the frequent occurrence of abiotic stresses, such as cold, drought and mineral deficiency. Generation of stress tolerant cultivars and rootstocks is crucial for the stable and sound development of citrus industry. There are some elite germplasms that can be integrated into breeding program. However, due to the polyembryony nature and other reproductive barriers it is challenging to transfer the tolerance from these elite germplasms into the targets. Genetic engineering is a rational approach for circumventing the reproductive barriers. Therefore, the genes cloned in our research projects can be used for genetic engineering of citrus to improve stress tolerance. The transgenic citrus plants generated in our laboratory can be incorporated into breeding pipeline in the future. These new germplasms provide a valuable resource to elucidate the mechanisms of stress response. Our research contributes to both fundamental and applied citrus research in China.
Selected publications (* corresponding author, as of March 2014)
- Huang XS, Wang W, Zhang Q, Liu JH(*). A basic Helix-Loop-Helix transcription factor PtrbHLH of Poncirus trifoliata confers cold tolerance and modulates POD-mediated scavenging of H2O2. Plant Physiology, 2013, 162: 178–1194 DOI:10.1104/pp.112.210740
- Sun PP, Zhu XF, Huang XS, Liu JH(*). Overexpression of a stress-responsive MYB transcription factor of Poncirus trifoliata confers enhanced dehydration tolerance and increases polyamine biosynthesis. Plant Physiology and Biochemistry, 2014, 78: 71-79
- Zhang XN, Li X, Liu JH(*). Identification of conserved and novel cold-responsive microRNAs in trifoliate orange (Poncirus trifoliata (L.) Raf.) using high-throughput sequencing. Plant Molecular Biology Reporter, 2014, 32(2): 328-341
- Liu JH(*), Peng T, Dai WS. Critical cis-acting elements and interacting transcription factors: key players associated with abiotic stress responses in plants. Plant Molecular Biology Reporter, 2014, 32(2): 303–317
- Xian LH, Sun PP, Wu J, Hu SS, Liu JH(*). Molecular cloning and characterization of CrNCED1, a gene encoding 9-cis-epoxicarotenoid dioxygenase in Citrus reshni, with functions in tolerance to multiple abiotic stresses. Planta, 2014, 239(1): 61-77
- Gong XQ, Liu JH(*). Genetic transformation and genes for resistance to abiotic and biotic stresses in Citrus and its related genera. Plant Cell, Tissue & Organ Culture, 2013, 113 (2): 137-147 DOI 10.1007/s11240-012-0267-x
- Fu XZ, Liu JH(*). Transcriptional profiling of canker-resistant transgenic sweet orange (Citrus sinensis Osbeck) constitutively overexpressing a spermidine synthase. BioMed Research International, 2013, doi.org/10.1155/2013/918136
- Fu XZ, Zhang YX, Gong XQ, Wang Y, Liu JH(*). Different transcriptional response to Xanthomonas citri subsp. citri between kumquat and sweet orange with contrasting canker tolerance. PLoS ONE, 2012, 7(7): e41790.
- Peng T, Zhu XF, Sun PP, Fan QJ, Liu JH(*). Identification and characterization of low temperature stress responsive genes in Poncirus trifoliata by suppression subtractive hybridization. Gene, 2012, 492(1): 220-228 DOI:
- Wang BQ, Zhang QF, Liu JH, Li GH. Overexpression of PtADC confers enhanced dehydration and drought tolerance in transgenic tobacco and tomato: effect on ROS elimination. Biochemical and Biophysical Research Communications, 2011, 413: 10-16
- Huang XS, Huo T, Fu XZ, Fan QJ, Liu JH (*). Cloning, molecular characterization of a mitogen-activated protein kinase gene from Poncirus trifoliata and its ectopic expression confers dehydration/drought tolerance in transgenic tobacco. Journal of Experimental Botany, 2011, 62(14): 5191–5206,
- Fu XZ, Chen CW, Wang Y, Liu JH(*), Moriguchi T. Ectopic expression of MdSPDS1 in sweet orange (Citrus sinensis Osbeck) reduces canker susceptibility: involvement of H2O2 production and transcriptional alteration. BMC Plant Biology, 2011, 11: 55
- Wang J, Sun PP, Chen CL, Wang Y, Fu XZ, Liu JH(*). An arginine decarboxylase gene PtADC from Poncirus trifoliata confers abiotic stress tolerance and promotes primary root growth in Arabidopsis. Journal of Experimental Botany, 2011, 62(8): 2899-2914
- Fu XZ, Khan EU, Hu SS, Fan QJ, Liu JH(*). Overexpression of the betaine aldehyde dehydrogenase gene from Atriplex hortensis enhances salt tolerance in the transgenic trifoliate orange (Poncirus trifoliata L. Raf.). Environmental and Experimental Botany, 2011, 74: 106-113 doi:10.1016/j.envexpbot.2011.05.006
- Huang XS, Liu JH(*), Chen XJ. Overexpression of PtrABF gene, a bZIP transcription factor isolated from Poncirus trifoliata, enhances dehydration and drought tolerance in tobacco via scavenging ROS and modulating expression of stress-responsive genes. BMC Plant Biology, 2010, 10: 230,
- Shi J, Fu XZ, Peng T, Huang XS, Fan QJ, Liu JH (*). Spermine pretreatment confers dehydration tolerance of citrus in vitro plants via modulation of antioxidative capacity and stomatal response. Tree Physiology, 2010, 30 (7): 914-922 doi: 10.1093/treephys/tpq030
- Liu JH, Ban Y, Wen XP, Nakajima I, Moriguchi T. Molecular cloning and expression analysis of an arginine decarboxylase gene from peach (Prunus persica). Gene, 2009, 429 (1-2): 10-17
- Liu JH, Kitashiba H, Wang J, Ban Y, Moriguchi T. Polyamines and their ability to provide environmental stress tolerance to plants. Plant Biotechnology, 2007, 24: 117-126
- Liu JH, Nada K, Honda C, Kitashiba H, Wen XP, Pang XM, Moriguchi T. Polyamine biosynthesis of apple callus under salt stress: importance of the arginine decarboxylase pathway in stress response. Journal of Experimental Botany, 2006, 57: 2589-2599
- Liu JH, Nada K, Pang XM, Honda C, Kitashiba H, Moriguchi T. Roles of polyamines in peach fruit development and storage. Tree Physiology, 2006, 26: 791-798