title: Introgression of opaque2 into Waxy Maize Causes Extensive Biochemical and Proteomic Changes in Endosperm.
abstract: Waxy maize is prevalently grown in China and other countries due to the excellent characters and economic value. However, its low content of lysine can't meet the nutritional requirements of humans and livestock. In the present study, we introgressed the opaque2 (o2) allele into waxy maize line Zhao OP-6/O2O2 by using marker-assisted selection (MAS) technique and successfully improved the lysine content and quality of waxy maize. Transcript abundance analysis indicated that the wx1 expression levels had no difference between Zhao OP-6/o2o2 and Zhao OP-6/O2O2. However, Zhao OP-6/o2o2 was characterized by a phenotype of hard and vitreous kernels and accumulation of protein bodies at smaller size (one third of that of parents) but in larger numbers. Biochemical analyses showed that Zhao OP-6/o2o2 had 16.7% less free amino acids than Zhao OP-6/O2O2, especially those derived from glycolytic intermediates, but its content of lysine was increased by 51.6% (0.47% vs. 0.31%). The content of amylopectin was 98.5% in Zhao OP-6/o2o2, significantly higher than that in Zhao OP-6/O2O2 (97.7%). Proteomic analyses indicated that o2 introgression not only decreased the accumulation of various zein proteins except for 27-kDa γ-zein, but also affected other endosperm proteins related to amino acid biosynthesis, starch-protein balance, stress response and signal transduction. This study gives us an intriguing insight into the metabolism changes in endosperm of waxy maize introgressed with opaque2.
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Beijing Key Lab of Plant Resource Research and Development, Beijing Technology and Business University, Beijing, China.
authors.forename: Liya
authors.initials: L
authors.lastname: Song
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Xinhai
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Na
authors.initials: N
authors.lastname: Yan
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Renpei
authors.initials: R
authors.lastname: Xia
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Weng
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Zhuanfang
authors.initials: Z
authors.lastname: Hao
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Degui
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Yong
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Mingshun
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Crop Genetics and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Shihuang
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000483:Alleles; D000687:Amylopectin / Q000235:genetics / Q000378:metabolism; D056625:Endosperm / Q000235:genetics / Q000378:metabolism*; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D055314:Seed Storage Proteins / Q000235:genetics / Q000378:metabolism*; D003313:Zea mays / Q000235:genetics / Q000378:metabolism*
chemical_list: D020543:Proteome; D055314:Seed Storage Proteins; D000687:Amylopectin