Nucleic acids encoding lettuce big-vein viral proteins and utilization thereof

Abstract

The coat protein of lettuce big-vein virus (LBVV) was purified from highly purified LBVV, and its partial amino acid sequences were determined. An RNA encoding the coat protein of LBVV was cloned by polymerase chain reaction using primers designed based on the determined amino acid sequences information, and its primary structure was elucidated. Moreover, the present inventors succeeded not only in isolating RNA molecules of a plurality of LBVV-encoded proteins, including LBVV polymerase, by carrying out 3′RACE and 5′RACE using primers designed based on the resulting sequence information, but also in determining their primary structure. It was found that the use of these made it possible to produce lettuce resistant to LBVV and to diagnose infections with LBVV.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a divisional of U.S. patent application Ser. No. 10 / 276,968, having a 35 U.S.C. § 371 date of Jan. 17, 2003, the disclosure of which is incorporated by reference herein in its entirety. U.S. patent application Ser. No. 10 / 276,968 is a 35 U.S.C. § 371 national phase filing of International Application No. PCT / JP01 / 04268, filed May 22, 2001. PCT / JP01 / 04268 claims priority to JP 2000-154440, filed May 22, 2000 and JP 2001-65339, filed Mar. 8, 2001.TECHNICAL FIELD [0002] The present invention relates to nucleic acids encoding lettuce big-vein viral proteins, proteins encoded by the nucleic acids, and their production and use. BACKGROUND ART [0003] Lettuce big-vein virus (LBVV) is a virus belonging to Varicosavirus, is composed of two RNAs (7.0 kb and 6.5 kb RNA), and retains a coat protein of 48 kDa. LBVV is a soil-borne virus that is spread in the soil by Olpidum brassicae, and occurs in the United States, Austra...

AI Technical Summary

Benefits of technology

The present invention relates to the isolation and characterization of genes and nucleic acids encoding proteins of lettuce big-vein virus (LBVV), as well as the development of methods for diagnosis and treatment of LBVV infection. The invention aims to provide a way to protect lettuce from LBVV infection and improve its productivity. The isolated nucleic acids can be used to produce plants with resistance to LBVV. The invention also provides a method for detecting LBVV infection through the use of specific primers. The invention can help to improve the diagnosis and treatment of LBVV infection in lettuce.

Problems solved by technology

Since this virus infects lettuce and remarkably lowers its quality and yield, it is a serious problem in lettuce production.

Unfortunately, there has not yet been reported the existence of a gene that makes lettuce resistant to this virus.

Although several cultivars such as Entree, Sea Green and Pacific are commercially available as LBVV-resistant cultivars, their resistance is low.

Thus, there has not yet been found a radical solution to disease damage caused by LBVV.

However, isolation and purification of LBVV are extremely difficult for reasons such as the instability of the viral particles, tendency for viral particles to readily aggregate with each other, and extremely low concentration of the virus in plants.