The ability of 4-coumarate: coenzyme Aligase promoter from Populus tomentosa (Pto4CL1p) to drive expression of the GUS reporter gene and 4-coumarate: coenzyme Aligase gene in tobacco has been studied using transgenic plants produced by Agrobacterium-mediated transformation. Intense GUS histochemical staining was detected in the xylem of stem in transgenic tobacco plants carrying the 1140 bp Pto4CL1p promoter. To further investigate the regulation function of the tissue-specific expression promoter, Pto4CL1p, a binary vector containing Pto4CL1p promoter fused with 4CL1 gene was transferred into tobacco. The activity of the 4CL1 enzyme doubled in the stems of transgenic tobacco but did not increase in the leaves. The content of lignin was increased 25% in the stem but there was no increase in the leaves of transgenic tobacco.

Lignin is a complex aromatic polymer of vascular plants that provides mechanical strength to the stem and protects cellulose fibres from chemical and biological degradation. 4-Coumarate: CoAligases (EC 6.2.1.12) are key enzymes for the biosynthetic pathway of monolignols which is an important complex aromatic polymer for lignin biosynthesis and tree growth. Recently, 4-coumarate: CoA ligase has been used as exogenous gene in transgenic plants to genetically modify the lignin biosynthesis pathway. Since most lignin is produced in the vascular cells, a tissue-specific-expressed promoter in the vascular cell would be important and useful to change and modify the content of lignin. Here we eport the existence of a promoter of GRP1.8 (the glycine-rich protein 1.8) in Sopho japonica L. (GenBank accession number AF250149) and studies on its function in transgenic tobacco. The promoter activity was analyzed in transgenic tobacco plants by histochemical staining of GUS gene expression driven by a 613-bp sjGRP1.8p promoter sequence. In sjGRP1.8p-GUS transgenic plants, intense GUS staining was detected in the xylem of the stem. To further investigate the regulation of the tissue-specific xpression of the 4CL1 gene, we analyzed the activity of the 4CL1 gene which is sense orientated with the sjGRP1.8p promoter in transgenic tobacco. The Pto4CL1 gene was expressed in the stem of ransgenic tobacco. The activity of the 4CL1 enzyme was increased 1-2-fold in the stem but not increased in the leaves of transgenic tobacco. In comparison with the control plants, the content of lignin was ncreased 25% in the stem but there was no increase in the leaves of transgenic tobacco.

利用电子显微镜和光学显微镜中相差和微分干涉等技术对胡杨（Populus euphratica Oliv.）悬浮培养的细胞和试管苗的组织和细胞结构以及盐胁迫对其结构影响进行了研究。与毛白杨（P. tomentosa Carr.）相比，胡杨存在与 耐盐相关的结构，如根尖具有较发达的表皮和外皮层，根毛着生靠近根端；叶片输导组织不发达；细胞中线粒体和 质体较丰富。盐胁迫和渗透胁迫可使胡杨细胞质中的线粒体和质体变得更为丰富，质体中内含体增多，在细胞质 中和液泡内缘出现明显的嗜锇物质，在悬浮培养的细胞内表现出明显的丝状结构，细胞核变大，核仁明显。受到8 g/L NaCl胁迫的胡杨根尖分生细胞仍可维持正常的结构。在超微结构研究中还发现，胡杨细胞膜与细胞壁之间呈 齿状结合，说明了膜与壁之间结合的牢固性和稳定性，解释了胡杨细胞在胁迫中不易发生质壁分离的原因。

研究了离体条件下胡杨（Populus euphratica Oliver）茎段、叶片及愈伤组织的器官发生和植株再生技术。离体培养以Ms为基本培养基并附加40mg/L腺嘌呤和500mg/L水解乳蛋白。离体叶片和茎段在BA为0.5ms/L和NAA为0.5mg/L的培养基上诱导产生愈伤组织，并在含0.25mg/LBA和0.5ms/LNAA的培养基上继代增殖。BA为0.5mg/L和NAA为0.1mg/L可诱导叶片和愈伤组织发生不定芽，诱导频率分别为100%和82.9%，对于茎段，BA和NAA分别为0.1mg/L和0.01mg/L时诱导不定芽频率可达83%。试管苗在大量元素减半并附加0.015mg/LNAA的MS培养基上诱导生根，生根率达86.2%。