Research Areas

Plant Molecular Genetics and Functional Genomics

NKLPMG mainly studies molecular genetics and functional genomics of important traits such as yield, quality and stress tolerance of rice, corn, tomato and other crops, to elucidate molecular mechanisms regulating important agronomic traits in crops by characterizing functional genes and regulatory factors and to provide the valuable genetic information for molecular crop breeding.

Primary Scientific Discoveries

Map-based cloning and functional analysis of a quantitative trait locus OgTT1 confering thermotolerance to rice
Climate change, mainly in the form of global warming, has been threatening many aspects of human life, e.g., by reducing crop yields due to frequent extremely hot weather. Breeding heat-tolerant crops using quantitative trait locus (QTL)/gene for plant thermotolerance is a fundamental way to help deal with this challenge. However, no QTLs underlying natural variation in thermotolerance have been cloned in crops. African rice (O. glaberrima) is more resistant to many abiotic stresses than Asian rice (O. sativa). By using map-based cloning, the research group led by Dr. Hongxuan Lin identified a major QTL from African rice (Oryza glaberrima), Thermo-Tolerance 1 (TT1), which enhances rice thermotolerance at both the vegetative and reproductive stages. TT1 encodes an α2 subunit of the 26S proteasome involved in the degradation of ubiquitinated proteins that were denatured due to heat stress, thereby responding to high temperatures. Ubiquitome analysis indicated that the stronger allele (OgTT1) of TT1 derived from Oryza glaberrima protects cells from heat stress through more efficient elimination of cytotoxic denatured proteins and the maintenance of heat response processes. TT1 is selected by climatic temperature, and plays an important role in local adaptation during rice evolution. Overexpression of OgTT1 markedly enhanced thermotolerance in rice (Oryza sativa), Arabidopsis and Festuca elata. This discovery may lead to an increase in crop security under the ongoing threat of global warming.
This work entitled “Natural alleles of a proteasome α2 subunit gene contribute to thermotolerance and adaptation of African rice” was published in Nat Genet (Li et al., 2015, 47: 827-832).

The molecular genetic mechanisms for rice complex quantitative traits —— The Second Prize of National Natural Science Award (2012)
Principal Achievers: Hongxuan Lin, Jiping Gao, Zhonghai Ren, Xianjun Song, Jian Jin
- The team first isolated a rice QTL for salt tolerance, SKC1, and suggested that SKC1 was involved in regulating K⁺/Na⁺ homeostasis under salt stress, providing a potential tool for improving salt tolerance in crops (Nat Genet, 2005);
- The team reported the cloning and characterization of GW2, a new QTL that controls rice grain width and weight, and provided insight into the mechanism of seed development, which was a potential tool for improving grain yield in crops (Nat Genet, 2007);
- The team showed that the PROG1 gene controlled wild-rice plant architecture, and demonstrated that artificial selection of the PROG1 during domestication led to the transition from the plant architecture of wild rice to that of domesticated rice (Nat Genet, 2008).

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