The haustorium and the chemistry of host recognition in parasitic angiosperms

Two parasitic angiosperms,Agalinis purpurea (Scrophulariaceae) andStriga asiatica (Scrophulariaceae), are compared as to the chemical recognition events involved in host selection.Agalinis is a hemiparasite which can mature to seed-set without a host, whereasStriga is a holoparasite and survives for only a very limited time without a host. Both parasites, however, attach to a host through a specialized organ known as the haustorium and regulate the development of this organ through the recognition of chemical factors from host plants. We now describe the discovery of 2,6-dimethoxy-p-benzoquinone (2,6-DMBQ) as an haustoria-inducing principle fromSorghum root extracts. Our investigation of this compound has led us to suggest that one level of host recognition in these parasitic plants is mediated through their enzymatic digestion of the host root surface. Degradation of surface components liberates quinonoid compounds, such as 2,6-DMBQ, which in turn trigger haustorial development.     

Logic programming to predict cell fate patterns and retrodict genotypes in organogenesis

Caenorhabditis elegans vulval development is a paradigm system for understanding cell differentiation in the process of organogenesis. Through temporal and spatial controls, the fate pattern of six cells is determined by the competition of the LET-23 and the Notch signalling pathways. Modelling cell fate determination in vulval development using state-based models, coupled with formal analysis techniques, has been established as a powerful approach in predicting the outcome of combinations of mutations. However, computing the outcomes of complex and highly concurrent models can become prohibitive. Here, we show how logic programs derived from state machines describing the differentiation of C. elegans vulval precursor cells can increase the speed of prediction by four orders of magnitude relative to previous approaches. Moreover, this increase in speed allows us to infer, or ‘retrodict’, compatible genomes from cell fate patterns. We exploit this technique to predict highly variable cell fate patterns resulting from dig-1 reduced-function mutations and let-23 mosaics. In addition to the new insights offered, we propose our technique as a platform for aiding the design and analysis of experimental data.     

红花细胞和组织培养研究进展

红花是重要的油药两用作物,本文对红花细胞和组织培养的国内外研究进展进行了综述,主要包括愈伤组织的诱导、次生代谢产物的合成及细胞的大规模培养、器官发生、体细胞胚胎发生等几个方面,并对该领域的发展前景进行了展望.     

Grow with the Flow: When Morphogenesis Meets Microfluidics

Developmental biology has advanced the understanding of the intricate and dynamic processes involved in the formation of an organism from a single cell. However, many gaps remain in the knowledge of embryonic development, especially regarding tissue morphogenesis. A possible approach to mimic such phenomena uses pluripotent stem cells in in vitro morphogenetic models. Herein, these systems are summarized with emphasis on the ability to better manipulate and control cellular interfaces with either liquid or solid materials using microengineered tools, which is critical for attaining deeper insights into pattern formation and stem cell differentiation during organogenesis. The role of conventional and customized cell‐culture systems in supporting important advances in the field of morphogenesis is discussed, and the fascinating role that material sciences and microengineering currently play and are expected to play in the future is highlighted. In conclusion, it is proffered that continued microfluidics innovations when applied to morphogenesis promise to provide important insights to advance many multidisciplinary fields, including regenerative medicine.     

Advances and Perspectives in Tissue Culture and Genetic Engineering of Cannabis

For a long time, Cannabis sativa has been used for therapeutic and industrial purposes. Due to its increasing demand in medicine, recreation, and industry, there is a dire need to apply new biotechnological tools to introduce new genotypes with desirable traits and enhanced secondary metabolite production. Micropropagation, conservation, cell suspension culture, hairy root culture, polyploidy manipulation, and Agrobacterium-mediated gene transformation have been studied and used in cannabis. However, some obstacles such as the low rate of transgenic plant regeneration and low efficiency of secondary metabolite production in hairy root culture and cell suspension culture have restricted the application of these approaches in cannabis. In the current review, in vitro culture and genetic engineering methods in cannabis along with other promising techniques such as morphogenic genes, new computational approaches, clustered regularly interspaced short palindromic repeats (CRISPR), CRISPR/Cas9-equipped Agrobacterium-mediated genome editing, and hairy root culture, that can help improve gene transformation and plant regeneration, as well as enhance secondary metabolite production, have been highlighted and discussed.     

Embryonic development of the alimentary canal of the scorpionfly Panorpa obtusa Cheng (Mecoptera: Panorpidae)

The embryonic origin of the alimentary canal, especially the midgut, is a controversial problem in insects, and it has not been satisfactorily resolved to date. The organogenesis of the digestive system in the embryonic development was observed in the scorpionfly Panorpa obtusa Cheng using light, transmission, and scanning electron microscopy. The embryonic development lasts about 150–160 h at 24°C. The stomodaeum is formed from an invagination in the medioposterior portion of the protocephalon mid‐ventrally posterior to the labral segment at 76 h after oviposition. The proctodaeum arises as an invagination from the caudal end of the abdomen at 78 h. Four anal forks are formed from within the opening of proctodaeum. Three pairs of proctodaeal evaginations are formed from the anterior part of the proctodaeum, and eventually developing into Malpighian tubules, thus are of ectodermal origin. The cardiac and pyloric valves develop from stomodaeum and proctodaeum, respectively, and also of ectodermal origin. The midgut epithelium originates from anterior and posterior midgut rudiments in blind ends of the stomodaeum and proctodaeum, and it is of endodermal origin. The two cell‐bands (rudiments) cover the yolk ventrally and then dorsally, elongate to each other, and eventually fuse to form the midgut. The midgut formation pattern is briefly discussed in different insects. Microsc. Res. Tech. 76:457–466, 2013. © 2013 Wiley Periodicals, Inc.     

Flax Improvement by Biotechnology Means

Abstract

The present paper is a short review of publications revealing development and optimization in tissue culture techniques (regeneration via organogenesis, somatic embryogenesis, anther cultures) and elaboration of efficient protocols for gene transfer as a tool for flax improvement. Different factors affecting the processes of in vitro regeneration and transformation are outlined. Perspectives in the area of bio-technological improvement of flax are discussed.