The sweet potato IbMYB1 gene as a potential visible marker for sweet potato intragenic vector system.
MYB transcription factors play important roles in transcriptional regulation of many secondary metabolites including anthocyanins. We cloned the R2R3-MYB type IbMYB1 complementary DNAs from the purple-fleshed sweet potato (Ipomoea batatas L. cv Sinzami) and investigated the expression patterns of IbMYB1 gene with IbMYB1a and IbMYB1b splice variants in leaf and root tissues of various sweet potato cultivars by reverse transcription-polymerase chain reaction. The transcripts of IbMYB1 were predominantly expressed in the purple-fleshed storage roots and they were also detectable in the leaf tissues accumulating anthocyanin pigments. In addition, transcript levels of IbMYB1 gene were up-regulated by treatment with methyl jasmonate or salicylic acid in leaf and root tissues of cv. White Star. To set up the intragenic vector system in sweet potato, we first evaluated the utilization of the IbMYB1 gene as a visible selectable marker. The IbMYB1a was transiently expressed in tobacco leaves under the control of a constitutive cauliflower mosaic virus 35S promoter, a root-specific and sucrose-inducible sporamin promoter, and an oxidative stress-inducible sweet potato anionic peroxidase2 promoter. We also showed that overexpression of IbMYB1a induced massive anthocyanin pigmentation in tobacco leaves and up-regulated the transcript levels of the structural genes in anthocyanin biosynthetic pathway. Furthermore, high-performance liquid chromatography analysis revealed that the expression of IbMYB1a led to production of cyanidin as a major core molecule of anthocyanidins in tobacco leaves. These results suggest that the IbMYB1 gene can be applicable to a visible marker for sweet potato transformation with intragenic vectors, as well as the production of anthocyanin as important nutritive value in other plant species.
Kim
Cha Young
CY
Bioindustrial Process Center, Korea Research Institute of Bioscience and Biotechnology, Jeonbuk 580-185, Korea.
Ahn
Young Ock
YO
Kim
Sun Ha
SH
Kim
Yun-Hee
YH
Lee
Haeng-Soon
HS
Catanach
Andrew S
AS
Jacobs
Jeanne M E
JM
Conner
Anthony J
AJ
Kwak
Sang-Soo
SS
D000085:Acetates / Q000494:pharmacology; D017398:Alternative Splicing; D000872:Anthocyanins / Q000096:biosynthesis*; D003517:Cyclopentanes / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D005819:Genetic Markers; D005822:Genetic Vectors; D027723:Ipomoea batatas / Q000235:genetics* / Q000378:metabolism; D054883:Oxylipins / Q000494:pharmacology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D035281:Plant Tubers / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D020156:Salicylic Acid / Q000494:pharmacology; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014170:Transformation, Genetic
D000085:Acetates; D000872:Anthocyanins; D003517:Cyclopentanes; D018076:DNA, Complementary; D005819:Genetic Markers; D054883:Oxylipins; D010940:Plant Proteins; D020033:Protein Isoforms; D018749:RNA, Plant; D014157:Transcription Factors; C072239:methyl jasmonate; D020156:Salicylic Acid