Page 5 - Molecular Plant Breeding

Molecular Plant Breeding 2011, Vol.2, No.5, 30 -36
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30
Research Report Open Access
Integrating the hrap Gene from Sweet Pepper into Potato Enhances Resistance
to Phytopthora infestans
Xianqun Huang 1 , Minhua Jiang 1 , Jian Chen 2,3 , Zhenyu Zhu 1 , Li Li 1 , Yingping Dong 1 , Zhongping
Lin 2
1. Guizhou Key Laboratory of Agricultural Biotechnology, Guizhou Institute of Biotechnology, Guiyang, 550006, P.R. China
2. College of Life Science, Peking University, Beijing, 100816, P.R. China
3. Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, P.R. China
Corresponding author email: xqhuang2005@163.com; Author
Molecular Plant Breeding, 2011, Vol.2 No.5 doi: 10.5376/mpb.2011.02.0005
Received: 13, Dec., 2010
Accepted: 12, Jan., 2011
Published: 01, Mar., 2011
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Huang et al., 2011, Integrating the hrap Gene from Sweet Pepper into Potato Enhances Resistance to Phytopthora infestans, Molecular Plant Breeding Vol.2
No.5 (doi: 10.5376/mpb.2011.02.0005)
Abstract Phytopthora infestans, also known as potato late blight, is a serious and widespread disease of potato that causes
significant yield losses in potato production every year. Controlling this destructive disease has become a great challenge for potato
farmers. In order to minimize commercial losses and improve tuber quality, it is a smart way to build potato disease resistant capacity
by the path of transgenic genetic improvement. In this present study, a gene encoding the hypersensitive response-assisting protein
(hrap) originally isolated from sweet pepper induced with the harpinPss-mediated hypersensitive response (HR) was introduced to the
potato variety Burbank mediated by Agrobacterium tumefaciens. The rate of transgenic acquisitions was 61.15% positive detected by
PCR, whereas 53.85% of the PCR positive plants were validated by southern blot assay. RT-PCR analysis showed that the hrap gene
was integrated into the potato genome and expressed in the transgenic potatoes. The sequence of the hrap gene isolated from
transgenic potato was 99.3% similarity identified with that of the hrap genes deposited in GenBan (GenBank: AF168415). The
resistant assay was performed by artificially incubating the pathogens of P. infestans. The results showed that the transgenic potatoes
exhibit the resistant enhancement.
Keywords Potato; Hrap gene; Phytopthora infestans Agrobacterium; mediated transformation
Background
China is recognized as the world’s largest producer of
potatoes (Solanum tuberosum L.) with over 490 million
hm2 in cultivation based on calculation of perennial
cultivating basis. Guizhou, a province located in
Southwest China, is deemed to be the largest producer
of potatoes in this country in 2006, with a planting area
of 590,000 hm2 (Source from: China Agricultural
Yearbook in 2007). Potatoes are subject to a variety of
potential diseases, such as Phytopthora infestans also
called as late blight, which is responsible for significant
historical crop losses, the most notorious of which was
the Irish potato famine in the 19th century. If this crop is
infected with late blight, the yield of potato will lose
with poor quality, irregular shape and appearance. It
was reported that economic losses related to infection
of P. infestans totally are more than 1 billion U.S.
dollars in China every year. Definitely, P. infestans is
also a particular problem in the subtropical,
high-humidity areas of Guizhou as well as the neighbor,
Yunnan provinces (Song et al, 1996), where
temperatures are mild and rainfall are high. Based on
the basic geographic and climate data, the International
Potato Center (CIP, Lima, Peru) completed computer
simulations of China's potato production, incorporating
the characteristics of P. infestans infection, and
concluded that the fungicide spray times need at least
nine times in Southwest China higher than that in other
potato-growing regions of the country, the actual
fungicide spray times of the latter were only five times
for P. infestans control (He et al, 1999). Unfortunately,
with the increasement of the chemical application, the
pathogen had acquired the pesticide resistances and
there is a serious public concern arised due to the direct