植物体的碳稳定同位素组成主要由植物本身的生物学特性决定，但环境胁迫对其影响也十分明显。综述了碳稳定同位素技术在研究植物水分利用效率、生物量高低及判断历史气候依据等研究领域的进展，阐明了植物体的δ13C值对干旱、盐分及其它环境因素的变化所引起的水分胁迫的响应，并对碳稳定同位素对水分胁迫的响应机理进行了归纳和推断。

水体沉积物中酸可挥发性硫化物（AVS）是总硫含量中活性最高的部分，是沉积物中有毒重金属的重要结合形态，它的含量在很大程度上影响着沉积物重金属的生物有效性，从而作为沉积物中有毒重金属环境污染评价的一个重要指标；就十多年来水体沉积物中酸可挥发性硫化物（AVS）的研究进行了综述。概述了AVS的测定方法及其影响因素；探讨了水体沉积物中AVS含量时空变化的规律，同时就目前“同时可提取重金属”（SEM）与AVS摩尔浓度比值和水体沉积物重金属生物毒性关系的研究进行了概括和分析。

V79-8 is an abnormal cell line which does not have detectable G1 and G2 phases in its cell cycle. This cell line is derived from V79 cell line which has G1 phase but lacks G2 phase. By using an anti-sense approach, CDK4 gene expression was partially inhibited to find whether CDK4 might contribute to the lack of G1 phase in V79-8 cells. Anti-CDK4 anti-sense plasmid was constructed and used to transfect V79-8 cells. Clones of transfected cells (V79-8-asCDK4) were examined, in comparison with V79-8 cells. to determine its growth curve, cell doubling-time (GT), the level of CDK4 gene expression and the levels of expression of some other growth related genes. V79-8-asCDK4 cells showed a slower growth rate with a doubling time 2.5-h longer than that of V79-8 cells. A flow cytometry (FCM) analysis demonstrated that the 2.5h increse of the doubling time of V79-8-asCDK4 cells was mainly due to the appearance of G1 phase because its G2+ M phase was not significantly different from that of V79-8 cells. The decrease of CDK4 gene expression in V79-8-asCDK4 cells was shown by Northern-blot. Changes in the expression levels of the growth-related genes TGF-

用不同浓度Ca（NO3）2·4H2O（0.7、1.4、2.1gCa2+/kg土）对1年生的处在两种NaCl胁迫（10和20g/kg）处理下的木麻黄扦插苗进行化学调控，研究硝酸钙盐加氯化钠处理的木麻黄幼苗的生长量、木麻黄幼苗抗氧化酶系统活性和渗透调节渗透调节物质的含量的变化，研究结果表明：中度NaCl胁迫加硝酸钙处理下的木麻黄扦插苗的可深性的蛋白质含量增加，MDA含量降低说明膜脂过氧化作用减轻，而且抗氧化酶活性（SOD、POD）之间协调变化有利于提高清除自由基的速率，中度盐胁迫下钙盐可以促进木麻黄体内脯氨酸的积累；但重度NaCl胁迫下钙盐对木麻黄的调控作用不显著，重度盐胁迫下钙盐反而降低木麻黄SOD、POD活性和脯氨酸的含量，减弱了抗氧化酶系统对活性氧的清除作用，同时高浓度钙盐还会加重NaCl胁迫对木麻黄幼苗的损伤，这说明适量的钙盐有利于木麻黄幼苗抵抗盐胁迫能力的提高，而高浓度钙盐则可能会加重盐胁迫。

The effect of Cd, Pb stress on the activated oxygen scavenging system indicates that the content of chlorophyll, chlorophyll a/b ratio and the activity of CAT gradually decrease, the activity of SOD increases first and then decreases, and the activity of POD gradually increases with increasing concentrations of Cd and Pb. Between Cd and Pb there is synergism in the activated oxygen scavenging system. The results show that the stress of Cd and Pb can affect the scavenging system of activated oxygen and result in imbalance of activated oxygen metabolism.