Different For Zinc Concentration Of Maize Gene Expression Differences In Study

Zinc-deficiency, which affects the crop growth greatly, is a common problem. Maize is one of the most zinc-sensitive crops. The growth of maize is baffled under the zinc-deficiency condition. Zinc-deficiency of maize is a widespread problem in China, thus the research on the mechanism of maize injury under the zinc-deficiency condition is very important. In this research, suppression subtractive hybridization (SSH) was performed to isolate the differentially expressed cDNA fragments under the low-zinc, zinc-deficiency and zinc-sufficiency conditions, respectively. The molecular regulating mechanism of maize under the zinc-deficiency and low-zinc conditions are expected to be discovered.The maize seedlings treated with low-zinc, zinc-deficiency and zinc-sufficiency for 48h were used as materials. Then extraction of mRNA and synthesis of cDNA were conducted. After SSH, the forward-subtracted and reverse-subtracted libraries were built for maize seedlings treated with different zinc-supply. The results prove that there are differentially expressed genes under different zinc-supply conditions.When the maize seedlings treated with low-zinc and zinc-sufficiency were used as materials, the genes obtained from the SSH-cDNA libraries suggest: most of the up-regulated genes under the low-zinc condition have significant homology to the genes relative to protein synthesis, signal transduction and transcription factor, such as: Rab-2-A related gene fragment LS10,transcription factor related gene fragment LS8 and so on. On the other hand, most of the down-regulated genes under the low-zinc condition have significant homology to the genes relative to cell growth, energy metabolism and root fair growth, such as: cellulose synthase-like protein related gene fragment SL1,NADP-dependent malic enzyme related gene fragment SL5 and so on.When the maize seedlings treated with zinc-deficiency and zinc-sufficiency were used as materials, the genes obtained from the SSH-cDNA libraries suggest: most of the up-regulated genes under the zinc-deficiency condition have significant homology to the genes relative to cell growth and metabolism, such as: aspartic proteinase related gene fragment DS1, alto/keto redutase AKR related gene fragment DS3 and so on. On the other hand, most of the down-regulated genes under the zinc-deficiency condition have significant homology to the genes relative to transcription, signal transduction, such as: TFIIH basal transcription factor complex P34 subunit related gene fragment SD4, elongation factor related gene fragment SD5 and so on.When the maize seedlings treated with low-zinc and zinc-deficiency were used as materials, the genes obtained from the SSH-cDNA libraries suggest: when treated with low-zinc, the genes, such as S-adenosylmethionine decarboxylase related gene fragment LD2, nodulin protein related gene fragment LD6, are up-regulated. While the genes, such as: nitrilase-associated protein related gene fragment DL1, are down-regulated.When the maize seedlings treated with zinc-sufficiency were used as control, the coding products of the down-regulated gene fragment SL1 under the low-zinc condition and the down-regulated gene fragment SD4 under the zinc-deficiency condition have 91% identity to cellulose synthase-like protein and 93% identity to TFIIH basal transcription factor complex P34 subunit, respectively. This could be used to explain the mechanism of low-zinc and zinc-deficiency injury.