Effect of in vivo administered plant growth hormones on the development of amylase and protease during germination of indian bean (Dolichos lablab L. var. lignosus) seeds

The plant growth hormones — BA, GA₃ or IAA (alone or in combination) in single dose were injected into the centre of intact imbibed seed, germinated in the presence of water and monitored for root length, shoot length, and activities of α-amylase and proteases during a 10-day germination period of Indian bean seeds. A significant increase was noticed in the root length and shoot length compared to the respective controls. Injection of BA, GA₃ or IAA alone resulted in a significant increase in the activity of α-amylase. The increase in the activities of proteases (acidic, neutral and alkaline) was not affected with either BA or GA₃ during the early stage of germination, but the fall in their activities in the later stages of germination was suppressed. However, in vivo administration of IAA alone or in combination with BA or GA₃ resulted in faster and higher development of α-amylase and protease(s) activities. These results indicated that more than one hormone is necessary for inducing the development of α-amylase and proteases at early stages, and also responsible for maintaining the higher activities in the later stages of germination.     

Concomitant Staining of Mast and Parietal Cells in Human Gastric Mucosa

A simple technique for concomitant staining of mast and parietal cells in the same section is described. Mast cells were stained by alcian blue or astra blue in methanol-formalinacetic acid fixed biopsies of gastric mucosa. Parietal cells were visualized by Dolichos biflorus lectin binding.     

扁豆花粉发育的超微结构

用透射电镜对扁豆ＤｏｌｉｃｈｏｓｌａｂｌａｂＬ．的小孢子发生和雄配子体形成过程进行了观察。首次观察到扁豆花粉发育过程中,其质体与线粒体去分化、再分化发生于整个花粉发育过程中,并经历了两个去分化和再分化的周期。     

Affinity purification, physicochemical and immunological characterization of a galactose-specific lectin from the seeds of Dolichos lablab (Indian lablab beans)

A galactose-specific lectin has earlier been isolated from the seeds of Dolichos lablab in our laboratory by conventional protein purification methods. We now established conditions to bind the lectin on Sepharose-galactose gel in the presence of 1.5 M ammonium sulfate in Tris-buffered saline, pH 7.4. It can be specifically eluted with 0.3 M galactose. The purified lectin is a glycoprotein, binds to Con A, agglutinates erythrocytes, and has an apparent native molecular weight of 120 +/- 5 kDa. In SDS-PAGE under reducing conditions, it dissociates into two subunits of molecular mass (Mr) 31 and 29 kDa. Among a number of sugars tested for inhibitory activity of the lectin, galactose was found to be a potent inhibitor. Rabbit polyclonal antibody to the purified lectin specifically reacted with the lectin subunits in Western blot analysis and additionally, an antibody raised to the isolated 31 kDa subunit show reactivity with both the subunits. Amino terminal sequences of both the subunits are identical. The purified lectin is stable up to 40 degrees C with a pH optimum of 7.4. The lectin has a high content of acidic amino acids and lacks sulfur-containing amino acids. Chemical modification of the lectin with group-specific reagents indicates the possible role of histidine, lysine, and tyrosine residues in lectin activity.     

Formation of Bowman-Birk inhibitors during the germination of horsegram (Dolichos biflorus)

Three Bowman-Birk type inhibitors (HGGI-I, II and III), which appear in the cotyledons of 120 h germinated horsegram (Dolichos biflorus) seeds have been purified to homogeneity by size-exclusion chromatography and ion-exchange chromatography. HGGI-I, HGGI-II and HGGI-III differ from each other and from the dormant seed inhibitors in amino acid composition, molecular size and charge. The amino-terminal sequence analyses indicate that these inhibitors are derived from the isoinhibitors of the dormant seed by a limited proteolysis and not by de novo synthesis. These inhibitors differ from each other at their amino-terminus. HGGI-II identical to HGGI-I except for the loss of a single amino-terminal aspartyl residue, where as HGGI-III shows the loss of a pentapeptide. All the three inhibitors are potent competitive inhibitors of trypsin and chymotrypsin. The dissociation constants (K(i)s) for trypsin inhibition indicate that amino-terminal tail of the inhibitors play a role in trypsin binding probably through electrostatic interaction.     

喀斯特坡地拉巴豆地埂篱根及根-土复合体力学特性

为探索地埂篱在喀斯特坡地水土保持中的价值,在重庆市酉阳县喀斯特顺层坡种植拉巴豆地埂篱,通过对根系灰度扫描、化学成分(木质素、纤维素、半纤维素)测定,单根抗拉试验和根-土复合体抗剪/冲试验,分析拉巴豆地埂篱根及根-土复合体的力学特性及影响因素。结果表明:(1)拉巴豆根系全根指标根长、根表面积、根体积、根重均表现为中坡下坡上坡,优势径级为0.0d≤1.0 mm径级。全根根系纤维素的平均含量较木质素、半纤维素高,且与根系直径呈显著负相关。(2)根系平均极限抗拉力6.77 N、平均抗拉强度29.57 MPa。极限抗拉力与木质素含量呈对数函数正相关、与木质素/纤维素(木纤比)呈线性正相关,抗拉强度与纤维素含量、木纤比分别为对数函数正相关和负相关。(3)上坡位抗剪土样的根体积密度、根重密度和木纤比显著大于中、下坡;而抗冲土样的根体积密度、根重密度、纤维素和半纤维素含量则中坡较优,但不显著。(4)根系能有效提高土体抗剪性能,根-土复合体的内摩擦角与粘聚力均较对照裸地高,但仅上坡粘聚力存在显著性差异(较对照增大45.67%)。内摩擦角和抗冲指数均中坡、下坡较优,粘聚力最优值位于上坡位。根-土复合体的力学特性主要受根体积、根重、根表面积密度和纤维素的影响。综上,拉巴豆根及根-土复合体的力学特性主要贡献径级为0.0d≤1.0 mm径级,中、下坡细根量大且根-土复合体抗冲性能表现较优,上坡根-土复合体抗剪切能力最强,但抗冲性能较弱。在推广拉巴豆地埂篱时,尽量种植于地势较低缓的中、下坡,更能凸显水土保持效益。     

Molecular engineering of a small trypsin inhibitor based on the binding loop of horsegram seed Bowman-Birk inhibitor

Context: The Bowman-Birk inhibitors (BBIs) are currently investigated with renewed interest due to their therapeutic properties in cancer and other inflammatory disease treatment. The molecular mass of the BBI is a limitation, as sufficient amounts of the inhibitor do not reach the organs outside the gastrointestinal tract when administered orally.

Method: The anti-tryptic domain of HGI-III of horsegram (Dolichos biflorus) was cloned using the vector pET-20b (+) and expressed in E. coli BL21 (DE3) pLysS.

Results: Kinetic analysis of this anti-tryptic peptide (recombinant trypsin inhibitory domain (rTID)) reveals that it is a potent inhibitor of trypsin and human tryptase. The K_i (3.2?±?0.17?×?10^?8 M) establishes a very high affinity to bovine trypsin. rTID inhibited human lung tryptase (IC₅₀ 3.78?±?0.23?×?10^?7 M). The rTID is resistant to the digestive enzymes found in humans and animals.

Conclusion: These properties propagate further research on the use of rTID as a therapeutic for cancer and other related inflammatory diseases.