Isolation of mitogen-activated protein kinase SlMAPK12 gene and characterization of its expression pattern in Solanum lycopersicum
In nature, plants are often exposed to ever-changing external stimuli during their growth and development, including pathogen infection, drought, salinity and various other biotic and abiotic stresses. These extracellular stimuli are perceived by the plant through a highly elaborate signaling networ...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Zhejiang University Press
2012-09-01
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| Series: | 浙江大学学报. 农业与生命科学版 |
| Subjects: | |
| Online Access: | https://www.academax.com/doi/10.3785/j.issn.1008-9209.2011.10.141 |
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| Summary: | In nature, plants are often exposed to ever-changing external stimuli during their growth and development, including pathogen infection, drought, salinity and various other biotic and abiotic stresses. These extracellular stimuli are perceived by the plant through a highly elaborate signaling network, which leads to an adaptive stress response at cellular and organismal levels. A specific class of serine/threonine protein kinases, mitogen-activated protein kinases (MAPKs) play an important role in the transduction of various extra- and intracellular signals and are conserved throughout eukaryotes. Recently, increasing evidences indicate that MAPK (mitogen-activated protein kinase) has very important effects on plant growth and development, as well as stress resistance. As we know, current research on tomato (Solanum lycopersicum L.) MAPK gene is relatively limited. While the recently completed Genome Sequencing Project for tomato genome provides an opportunity to deduce the tomato MAPK genes and infer its evolutionary history. So more detailed biochemical and functional characterization is likely to be carried out to understand the function of tomato MAPKs.The cDNA sequence of novel SlMAPK12 (GenBank No. JF795447) was amplified by PCR using primers designed based on the predicted sequences of tomato unigene. Then many bioinformatics tools were used to analyze and predict SlMAPK12, such as ProtParam. To analyze the expression pattern of SlMAPK12 in various tissues and during flower developmental stages, the leaves, stems, petals, stamens, pistils, fruits and 5 stages of floral development from flowering tomato plants were characterized by RT-PCR and furthermore proved by qRT-PCR. For high temperature treatment, the stamen were collected at 0 h, 12 h,24 h,48 h and 72 h after (38±1)℃ heat stress treatment. Then the qRT-PCR experiments were employed to characterize gene expression profiles.SlMAPK12 encoding a protein of 621 amino acids contained 11 subdomains of the MAPK. Subdomain Ⅷ contained the threonine and tyrosine residues, named T-D-Y (Thr-Asp-Tyr) motif, that was phosphorylated for the activation of SlMAPK12. SlMAPK12 protein sequences were found to contain four types of special domains: active site, ATP binding site, substrate binding site, and activation loop (A-loop) and KIM docking site. Amino acid sequence alignment revealed that SlMAPK12 shared high identity with group-D MAPKs from Arabidopsis, Populus, and Ricinus, which indicated that the group-D MAPKs was conserved in different plant species.The temporal and spatial expression patterns of SlMAPK12 analysed by RT-PCR and qRT-PCR in different tomato tissue indicated that the relative gene expression level of SlMARK12 in stamen was much higher than other organs. Also, the levels of SlMAPK12 expressed in different developmental stages of tomato flower were almost the same. These results indicated that SlMAPK12 might have very important effects on flower development.The expression pattern of SlMAPK12 gene under high-temperature (38±1)℃ was analysed by qRT-PCR. We found that the transcripts of SlMAPK12 in stamen accumulated markedly when the tomato seedlings were subjected to heat stress. These results above indicated that SlMAPK12 probably involved in the adaptive responses to heat stress during tomato pollen development.The preferential expression of SlMAPK12 gene provides a new avenue for functional analyses in tomato. The major challenge for future research is to focus on identifying more MAPKs and understanding the specific role of MAPK genes during tomato growth and development. |
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| ISSN: | 1008-9209 2097-5155 |