[Chinese waxy elites SW70 and SW22 are revealed to be new multimutants of starch-synthesis enzyme coding genes].
Waxy maize (wx) is a type of spontaneous starch mutant as compared to wild type foodstuff maize (Wx). The mechanisms underlying waxy maize kernel development are intricate and diversified. Here we characterized the expression of 21 genes belonging to four families, i.e., ADP-glucose pyrophosphorylase (AGPase), starch synthase (SS), starch branching enzyme (SBE) and starch debranching enzyme (DBE) in the developing kernels of waxy maize inbred SW22, SW70 and relative wild type inbred 5003 at 1, 2 and 4 weeks after pollination. Dynamic expression pattern of a number of genes in developing kernels of SW22 were different from that in 5003 and SW70. Besides, obvious presence of wx transcripts in SW22 and SW70 were observed, though at the level lower than that in wild type 5003. Unexpectedly, the transcripts of Gbssllb and isoamylase-type DBE coding gene Iso2 were completely absent in SW22 and SW70. The above observation prompted the hypothesis that partial or complete loss-of-function of Wx, and/or there exist lose-of-function of uncharacterized gene (s) important for amylose synthesis in SW22 such as GbssIIb and Iso2, which may account for the absence of amylose accumulation in SW22.
Ding
Xiang Zhen
XZ
College of Life Sciences, Shanxi Normal University, Linfen 041104.
Yang
Ming Ming
MM
Wang
Bei Guo
BG
Yan
Gui Qin
GQ
Duan
Ke
K
Huang
Jian Hua
JH
D015061:1,4-alpha-Glucan Branching Enzyme / Q000235:genetics; D000688:Amylose / Q000378:metabolism; D017343:Genes, Plant / Q000235:genetics; D051599:Glucose-1-Phosphate Adenylyltransferase / Q000235:genetics; D009154:Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013214:Starch Synthase / Q000235:genetics; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
D000688:Amylose; D015061:1,4-alpha-Glucan Branching Enzyme; D013214:Starch Synthase; D051599:Glucose-1-Phosphate Adenylyltransferase