印度喜马偕尔邦两种松树根际线虫新种

描述了来自印度喜马偕尔邦的两种松树根际线虫新种。线虫新种Ogma varispinosum sp.n.， 分离自喜马拉雅长叶松(Pinus roxburghii Sarg.)，雌虫特征：L(体长)=0.41~0.46 mm;a(体长/最 大体宽)=10.5~12.7;b(体长/体前端至食道与肠连接处的距离)=3.2~3.5;c(体长/尾长)=11.0~13.4;c ′(尾长/肛门处体宽)=1.3~2.3;V(阴门至头顶距离×100/体长)=83.9 %~85.7 %;Stylet(口针长)为 86~88 μm;R(体环数)为77~81;Res(唇盘与贲门瓣之间的体环数)为23~25;RV(阴门与尾端之间的体环 数)=12~13;RV-an(肛门与阴门之间的体环数)=4~6;8~9纵行的鳞片，第1行为环纹形状。另一线虫新 种O.ornamentum sp.n，分离自乔松(P.wallichiana A.B.Jacks)。雌虫特征：L=0.31~037 mm;a=8.2~11.6;b=3.2~3.8;c=6.8~8.5;V=82.0 %~84.9 %;Stylet为69.9~72.0 μm;R=59~62;Res=16~18;Rex=20;RV=11~12;RV-an=1~2;具有特殊的表皮结构。     

CO2 regulator SLAC1 and its homologues are essential for anion homeostasis in plant cells

The continuing rise in atmospheric [CO2] is predicted to have diverse and dramatic effects on the productivity of agriculture, plant ecosystems and gas exchange. Stomatal pores in the epidermis provide gates for the exchange of CO2 and water between plants and the atmosphere, processes vital to plant life. Increased [CO2] has been shown to enhance anion channel activity proposed to mediate efflux of osmoregulatory anions (Cl- and malate(2-)) from guard cells during stomatal closure. However, the genes encoding anion efflux channels in plant plasma membranes remain unknown. Here we report the isolation of an Arabidopsis gene, SLAC1 (SLOW ANION CHANNEL-ASSOCIATED 1, At1g12480), which mediates CO2 sensitivity in regulation of plant gas exchange. The SLAC1 protein is a distant homologue of bacterial and fungal C4-dicarboxylate transporters, and is localized specifically to the plasma membrane of guard cells. It belongs to a protein family that in Arabidopsis consists of four structurally related members that are common in their plasma membrane localization, but show distinct tissue-specific expression patterns. The loss-of-function mutation in SLAC1 was accompanied by an over-accumulation of the osmoregulatory anions in guard cell protoplasts. Guard-cell-specific expression of SLAC1 or its family members resulted in restoration of the wild-type stomatal responses, including CO2 sensitivity, and also in the dissipation of the over-accumulated anions. These results suggest that SLAC1-family proteins have an evolutionarily conserved function that is required for the maintenance of organic/inorganic anion homeostasis on the cellular level.