Induction of Hairy Roots on Somatic Embryos of Rhizoclones from Typha domingensis Seedlings

Abstract

A protocol for the induction of hairy roots on somatic embryos of rhizoclones from Typha domingensis seedlings grown in hydroponic rhizotron systems was established for the first time. Rhizogenesis was induced through the agrotransformation of somatic embryos in oblong and scutellar states of development using the K599, LBA9402, and A4 strains of Agrobacterium rhizogenes. The transfection to the embryos was performed by cocultivation of rhizoclones on a Murashige and Skoog mineral medium at 50% strength (MS0.5), in the dark, at 28 ± 2 °C for 72 h. In contrast to nontransformed embryos that did not exhibit any root tissue, transformed embryos presented hairy roots that varied in number, length, and density depending on the bacterial strain, and K599 was the most effective strain. After analysis via optical microscopy, the transformed embryos were collected and transferred to fresh culture media supplemented with 400 mg mL−1 cefotaxime and 10 mg L−1 ascorbic acid. The efficiency of transformation and survival of the oblong and scutellar embryos were similar among the three bacterial strains. The results show that agrotransformation of somatic embryos of rhizoclones from T. domingensis is a novel and viable strategy for the generation of genetic transformants of Typha that have potential applications in bioremediation technologies.

Cation/Ca2+ Exchanger 1 (MdCCX1), a Plasma Membrane-Localized Na+ Transporter, Enhances Plant Salt Tolerance by Inhibiting Excessive Accumulation of Na+ and Reactive Oxygen Species

“…To obtain the composite plants with their roots genetically modified, the CDS of MdCCX1 was cloned into pCambia2300-GFP vector with MdCCX1-2300GFP-F and -2300GFP-R primers, and a selected specific 300-bp fragment of MdCCX1 was cloned into the RNAi vector pK7GWIWG2D, carrying a GFP tag for transformant selection. The resultant overexpression vector pCambia2300-MdCCX1-GFP, RNAi vector MdCCX1-RNAi-GFP, and two corresponding empty vectors were transferred into Agrobacterium rhizogenes K599 for genetic transformation of apple roots following the method previously reported (Xiang et al, 2005;Hernandez-Piedra et al, 2020). Briefly, onemonth-old tissue cultured apple seedlings were cut off at the base of the stem with a surgical blade leaving about 1.5 cm long stem to create a diagonal incision.…”