Efficiency of different Agrobacterium rhizogenes strains on hairy roots induction in Solanum mammosum

Abstract

This article presents the abilities and efficiencies of five different strains of Agrobacterium rhizogenes (strain ATCC 31798, ATCC 43057, AR12, A4 and A13) to induce hairy roots on Solanum mammosum through genetic transformation. There is significant difference in the transformation efficiency (average number of days of hairy root induction) and transformation frequency for all strains of A. rhizogenes (P < 0.05). Both A. rhizogenes strain AR12 and A13 were able to induce hairy root at 6 days of co-cultivation, which were the fastest among those tested. However, the transformation frequencies of all five strains were below 30 %, with A. rhizogenes strain A4 and A13 showing the highest, which were 21.41 ± 10.60 % and 21.43 ± 8.13 % respectively. Subsequently, the cultures for five different hairy root lines generated by five different strains of bacteria were established. However, different hairy root lines showed different growth index under the same culture condition, with the hairy root lines induced by A. rhizogenes strain ATCC 31798 exhibited largest increase in fresh biomass at 45 days of culture under 16 h light/8 h dark photoperiod in half-strength MS medium. The slowest growing hairy root line, which was previously induced by A. rhizogenes strain A13, when cultured in optimized half-strength MS medium containing 1.5 times the standard amount of ammonium nitrate and potassium nitrate and 5 % (w/v) sucrose, had exhibited improvement in growth index, that is, the fresh biomass was almost double as compared to its initial growth in unmodified half-strength MS medium.

Advances in Boerhaavia diffusa hairy root technology: a valuable pursuit for identifying strain sensitivity and up-scaling factors to refine metabolite yield and bioactivity potentials

“…The disparity in the maturity levels of the utilized explants could be one of the causes for the observed difference in susceptibility of the nodal segments, as the maturation status of explants predominantly impacts the availability of functionally competent cells (as well as their internal hormonal levels), which essentially serve as ideal targets for hairy root induction (Potrykus 1990). The currently documented preferentiality of B. diffusa leaf explants towards the three selected A. rhizogenes strains reiterates earlier observations where the transformation efficiencies of the ATCC 15834 and A4 strains have differed according to the plant system under study, and both their supremacies as well as failures have been documented earlier (Fu et al 2005;Ooi et al 2013;Setamam et al 2014). In tandem, the prevailing lesser compatibility threshold of the SA79 strain towards B. diffusa substantiated a previous report involving Catharanthus roseus (Batra et al 2004).…”

“…Seeing that A. rhizogenes strain specificity together with plant genotype and explants factors has played a crucial role in determining the overall success of the underlying transformation events (Ooi et al 2013), premeditated optimization of such decisive factors seemed realistic to reap the best advantage of applying this hairy root technology in B. diffusa. The presently observed exclusive susceptibility of leaf explants and total failure of stem segments towards A. rhizogenes-mediated hairy root induction contradict the earlier findings of Sahu et al (2013Sahu et al ( , 2014, who have demonstrated notable susceptibility of intermodal segments of in vivo-grown B. diffusa plants towards the peak limit of hairy root induction.…”

Influence of Agrobacterium rhizogenes strains on hairy root induction and ‘bacoside A’ production from Bacopa monnieri (L.) Wettst.

“…This could be due to differential virulence of these strains and/or host specificity (Zehra et al 1999;Porter 1991). Although, higher virulence of strain R1000 and strain SA79 for root induction have been reported earlier in many plants (Tiwari et al 2007;Tao and Li 2006), yet some studies reported that strain A4 is more efficient in root induction (Ooi et al 2013;Giri et al 2001). …”

Enhanced production of valerenic acid in hairy root culture of Valeriana officinalis by elicitation

“…The strain of Agrobacterium influences the development, growth rate and secondary metabolite production in transformed root cultures [32]. The A13 strain of A. rhizogenes is one of the aggressiveness strains whose superiority for hairy root induction and bioactive compound production have been reported in several other medicinal plants [33,34].…”