[Objective] ＂Tapping panel dryness （TPD）＂, a syndrome known as tapping incision blocked partly or entirely during latex exploiting, has become the most important factor causing great losses for rubber production. ...[Objective] ＂Tapping panel dryness （TPD）＂, a syndrome known as tapping incision blocked partly or entirely during latex exploiting, has become the most important factor causing great losses for rubber production. Aiming to elucidate the molecular mechanism of tapping panel dryness occurrence, this study carried out molecular cloning and bioinformatical analysis of a mRPL21 cDNA sequence, a gene associated with TPD. [Method] In a preliminary study, an expressed sequence tag （EST） encoding a deduced protein homologous to mitochondrial 50S ribosomal protein L21 （mRPL21）, which showed to be down-regulated in the latex of TPD-affected rubber trees, was isolated by suppression subtractive hybridization （SSH）. After ESTs assembling and RT-PCR validation, an 853 bp cDNA sequence with an open reading frame （ORF） was cloned, which was named as HbmRPL21 under GenBank accession number of HM230670. [Result] Bioinformatical analysis suggests that HbmRPL21 encodes a deduced polypeptide of 271 amino acids with a theoretical molecular weight （Mw） of 30.52 kDa and isolectric point （pI） of 8.40, and HbmRPL21 is a mitochondrion-targeted protein with a conserved domain of Ribosomal_L21p involving translation. Homology analysis reveals high amino acid sequence identity of mRPL21 from plants, while diversity of that between plant and animal kingdom. [Conclusion] This study laid the basis for further revealing the biological functions of mRPL21 in TPD-affected rubber trees.展开更多
The B2-L21 ordering transitions in Au-Cu-Al shape-memory alloys are studied by the Monte Carlo exchange simulations,where a set of the first,the second and the third nearest-neighbor mixing potentials for CuAl in the ...The B2-L21 ordering transitions in Au-Cu-Al shape-memory alloys are studied by the Monte Carlo exchange simulations,where a set of the first,the second and the third nearest-neighbor mixing potentials for CuAl in the Au-Cu-Al alloys are calculated from first principals using the Connolly-Williams methods.To ensure the phase stability of the β-Au-Cu-Al,the investigation includes the range of compositions Au2Cu1-xAl1+x (0.15≤x≤0.15).The B2-L21 transition temperatures are predicted,and are in agreement with the experimental results.The atomic ordering around vacancy of the L21 structure is further discussed.展开更多
基金Supported by the Fundamental Research Funds for Rubber Research Institute, CATAS (1630022011014)Key Science and Technology Project of Hainan Province (90107)+1 种基金Basic Scientific Research Operational Fund for Central-level Public-interest Research Institutes (YWFZX2010-9)Special Fund for Science and Technology Research of Public Welfare Trades ( nyhyzx07-033-1)~~
文摘[Objective] ＂Tapping panel dryness （TPD）＂, a syndrome known as tapping incision blocked partly or entirely during latex exploiting, has become the most important factor causing great losses for rubber production. Aiming to elucidate the molecular mechanism of tapping panel dryness occurrence, this study carried out molecular cloning and bioinformatical analysis of a mRPL21 cDNA sequence, a gene associated with TPD. [Method] In a preliminary study, an expressed sequence tag （EST） encoding a deduced protein homologous to mitochondrial 50S ribosomal protein L21 （mRPL21）, which showed to be down-regulated in the latex of TPD-affected rubber trees, was isolated by suppression subtractive hybridization （SSH）. After ESTs assembling and RT-PCR validation, an 853 bp cDNA sequence with an open reading frame （ORF） was cloned, which was named as HbmRPL21 under GenBank accession number of HM230670. [Result] Bioinformatical analysis suggests that HbmRPL21 encodes a deduced polypeptide of 271 amino acids with a theoretical molecular weight （Mw） of 30.52 kDa and isolectric point （pI） of 8.40, and HbmRPL21 is a mitochondrion-targeted protein with a conserved domain of Ribosomal_L21p involving translation. Homology analysis reveals high amino acid sequence identity of mRPL21 from plants, while diversity of that between plant and animal kingdom. [Conclusion] This study laid the basis for further revealing the biological functions of mRPL21 in TPD-affected rubber trees.
文摘The B2-L21 ordering transitions in Au-Cu-Al shape-memory alloys are studied by the Monte Carlo exchange simulations,where a set of the first,the second and the third nearest-neighbor mixing potentials for CuAl in the Au-Cu-Al alloys are calculated from first principals using the Connolly-Williams methods.To ensure the phase stability of the β-Au-Cu-Al,the investigation includes the range of compositions Au2Cu1-xAl1+x (0.15≤x≤0.15).The B2-L21 transition temperatures are predicted,and are in agreement with the experimental results.The atomic ordering around vacancy of the L21 structure is further discussed.
