A new mechanism for the surface regulation of the balance between broad-spectrum disease resistance and yield in rice.

On February 2, the international academic journal Science published online the latest research results on rice long-lasting broad-spectrum disease resistance by the He Zuhua Research Group of the Institute of Plant Physiology and Ecology of the Shanghai Institute of Life Sciences of the Chinese Academy of Sciences, entitled Epigenetic regulation of antagonistic receptors rice blast resistance with yield with balance.
the study successfully cloned the long-lasting broad-spectrum disease-resistant gene Pigm, and revealed a new epigenetic regulatory mechanism for the balance between broad-spectrum disease resistance and yield in rice.
rice plague is caused by the fungus Magaporthe oryzae, is one of the most important diseases of rice, distributed throughout the country and even the world's rice areas, can cause a large reduction in rice production, serious production reduction of 40% to 50%, or even no grain harvest, so China's new rice varieties from 2008 to implement the rice plague resistance "one vote veto" system.
most cost-effective way to control this disease is to discover and use new broad-spectrum long-lasting disease-resistant resources for the selection of new broad-spectrum disease-resistant varieties.
Up to now, 25 anti-rice pestilence genes have been cloned and functionally identified, but the vast majority of disease-resistant varieties with these genes are generally popularized 3 years later by rice pestilence bacteria to overcome loss of resistance, the application of rice disease-resistant breeding is greatly limited.
the other hand, the use of disease-resistant gene polymerization method can improve the disease resistance of rice but will affect yield and quality, that is, there is a disease-resistant cost problem.
In order to solve this bottleneck that has long plagued the plant pathology and breeding community, the he Zuhua team of plant ecology, in cooperation with breeders, began in 2002 to widely screen anti-plague species, from the breeding materials originating in China's farm varieties identified a broad-spectrum long-lasting anti-plague new bit Pigm.
methods of molecular genetics, molecular biology, biochemistry and cell biology are used to systematically analyze the long-lasting disease resistance mechanism of this new place.
study found that Pigm is a cluster of genes that contain multiple NBS-LRR-type disease-resistant genes.
only 2 of these proteins, PigmR and PigmS, are functional.
PigmR in rice leaves, stems, spikes and other organ composition of the expression, can be self-made to form a omogenous dommics, play a broad-spectrum disease resistance function, but PigmR led to a decrease in rice grain weight, yield decreased.
In contrast to PigmR, PigmS is regulated by epigenetics, which is expressed only in the pollen of rice, and is expressed very low in the tissue sites infested by pathogens such as leaves and stalks, but can improve the syringe rate of rice and offset the effect of PigmR on yield.
PigmS can compete with PigmR to form a broad-spectrum disease resistance of heterogeneous djure inhibitors of PigmR.
But because of the low level of PigmS expression, which provides a "sanctuary" for pathogens, the evolutionary choice pressure of pathogens becomes smaller, slowing the pathogenic evolution of PigmR, so Pigm-mediated resistance to disease is persistent.
the use of Pigm to improve the selection of varieties both broad-spectrum long-lasting disease resistance and does not affect the final yield.
this gene has been used by more than 30 seed companies and breeding units in rice disease-resistant molecular breeding, there have been new varieties to participate in regional trials and variety testing.
study not only theoretically expands the understanding of plant immunity and disease resistance mechanisms, but also provides effective new tools for crop disease-resistant breeding.
The work was mainly carried out by associate researcher Deng Yiwen and doctoral students Yan Keran, Xie Wei and Yang Dongyong under the guidance of He Zuhua, and was supported by the leading project of the Chinese Academy of Sciences, the national major special project for the cultivation of new genetically modified varieties, and the National Natural Science Foundation of China.
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