Ascophyllum nodosum: a Potential Substitute for Synthetic Hormones for Tissue Culture Propagation of Capparis decidua (Forsk) Edgew

Author(s):  
Jyoti Ahlawat ◽  
Anita R. Sehrawat ◽  
Ravish Chaudhary ◽  
Digvijay Pandey
Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 929
Author(s):  
Carloalberto Petti

Tissue culture is an essential requirement in plant science to preserve genetic resources and to expand naturally occurring germplasm. A variety of naturally occurring and synthetic hormones are available to induce the processes of dedifferentiation and redifferentiation. Not all plant material is susceptible to tissue culture, and often complex media and hormone requirements are needed to achieve successful plant propagations. The availability of new hormones or chemicals acting as hormones are critical to the expansion of tissue culture potentials. Phloroglucinol has been shown to have certain hormone-like properties in a variety of studies. Ornithogalum dubium, an important geophyte species, was used to characterise the potential of phloroglucinol as the sole plant-like hormone in a tissue culture experiment. Tissue culture, plant regeneration, total phenolic and genetic variability were established by applying a variety of methods throughout long-term experiments. Phloroglucinol did induce callus formation and plant regeneration when used as the sole supplement in the media at a rate of 37%, thus demonstrating auxin/cytokines-like properties. Callus formation was of 3 types, friable and cellular, hard and compact, and a mixture of the two. The important finding was that direct somatogenesis did occur albeit more frequently on younger tissue, whereby rates of induction were up to 52%. It is concluded that phloroglucinol acts as a “hormone-like” molecule and can trigger direct embryogenesis without callus formation.


In Vitro ◽  
1976 ◽  
Vol 12 (12) ◽  
pp. 797-813 ◽  
Author(s):  
Lynn R. Miller ◽  
Toshio Murashige

2020 ◽  
Vol 12 (560) ◽  
pp. eaba3312
Author(s):  
Marti Cabanes-Creus ◽  
Claus V. Hallwirth ◽  
Adrian Westhaus ◽  
Boaz H. Ng ◽  
Sophia H.Y. Liao ◽  
...  

Recent clinical successes in gene therapy applications have intensified interest in using adeno-associated viruses (AAVs) as vectors for therapeutic gene delivery. Although prototypical AAV2 shows robust in vitro transduction of human hepatocyte–derived cell lines, it has not translated into an effective vector for liver-directed gene therapy in vivo. This is consistent with observations made in Fah−/−/Rag2−/−/Il2rg−/− (FRG) mice with humanized livers, showing that AAV2 functions poorly in this xenograft model. Here, we derived naturally hepatotropic AAV capsid sequences from primary human liver samples. We demonstrated that capsid mutations, likely acquired as an unintentional consequence of tissue culture propagation, attenuated the intrinsic human hepatic tropism of natural AAV2 and related human liver AAV isolates. These mutations resulted in amino acid changes that increased binding to heparan sulfate proteoglycan (HSPG), which has been regarded as the primary cellular receptor mediating AAV2 infection of human hepatocytes. Propagation of natural AAV variants in vitro showed tissue culture adaptation with resulting loss of tropism for human hepatocytes. In vivo readaptation of the prototypical AAV2 in FRG mice with a humanized liver resulted in restoration of the intrinsic hepatic tropism of AAV2 through decreased binding to HSPG. Our results challenge the notion that high affinity for HSPG is essential for AAV2 entry into human hepatocytes and suggest that natural AAV capsids of human liver origin are likely to be more effective for liver-targeted gene therapy applications than culture-adapted AAV2.


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