Purification of a trypsin inhibitor from Cocculus hirsutus and identification of its biological activity

Proteinase inhibitors play a significant role in plant defense against insect pests and phytopathogens by inhibiting their proteases. A thermotolerant monomeric trypsin inhibitor with molecular weight ∼18kD was purified from Cocculus hirsutus (ChTI) using trypsin sepharose affinity column. Western blot analysis using ChTI IgY revealed its presence in vegetative parts and seeds. The second and third instar larvae of H. armigera fed with ChTI (5000TIU/ml) resulted in 84.59 and 58.71% reduction in mean larval weight respectively. An increase in the larval growth period was observed in ChTI fed larvae at all instars and inhibitor fed larvae could not complete their life cycle. ChTI caused 74 and 59.53% inhibition of bovine trypsin and Helicoverpa gut proteases respectively. ChTI exhibited strain specificity and inhibited growth and development of plant fungal pathogens. Bioassay studies on yeast strains indicated that ΔYNK and MNN1 are more sensitive to ChTI. The results suggest that phosphodiester linkage in cell wall components is likely to be the key determinants for binding of ChTI. Taken together, these studies indicate that ChTI is a potential candidate for development of transgenic plants against foliar diseases and insect pests

<i><span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;color:black;mso-ansi-language:EN-GB;mso-fareast-language:EN-US; mso-bidi-language:HI" lang="EN-GB">Agrobacterium</span></i><span style="font-size:11.0pt;font-family:"Times New Roman";mso-fareast-font-family: "Times New Roman";mso-bidi-font-family:Mangal;color:black;mso-ansi-language: EN-GB;mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB">-mediated transformation for development of transgenic tomato with <i>ySAMdc</i> gene</span>

19-25Tomato is an important model plant system for transformation and expression of genes related to different characteristics. Enhancement of lycopene content in tomato fruit is one of the important aspects in improvement of commercial genotypes. In the present study, tomato genotype Arka Vikas was selected for introduction of 488 bp ySAMdc gene under E8 fruit promoter through transformed Agrobacterium tumefaciens. The transformation efficiency was 16.7 and 14.2% in two trials. This resulted in the production of 7 putative transgenics in T0 generation and 4 in the T1 generation. In both the generations, the lycopene content was enhanced by 2 to 3-fold. The transgenic plants expressed slightly altered morphological and biochemical characteristics. The integration of gene was confirmed using reverse transcription-PCR after extraction of RNA