High-efficiency and stable genetic transformation of pear (Pyrus communis L.) leaf segments and regeneration of transgenic plants

Abstract

Pear (Pyrus communis L.) is a nutrient-dense fruit with strong consumer demand and high commercial value. However, most cultivated pear varieties are often susceptible to diseases caused by fungi, bacteria, and viruses. The purpose of the present study was to establish an efficient genetic transformation and regeneration protocol, paving the way for genetic engineering of pear cultivars with enhanced disease resistance. Major factors that influence transformation and regeneration were examined and optimal conditions were established for efficient transformation from leaf explants of 'Old Home', a valuable pear interstem and rootstock. High transformation efficiency was achieved largely due to an improved infection/transformation induction strategy. Co-cultivation of Agrobacterium cells and leaf segments on a liquid induction medium yielded a fivefold increase in transformation frequency. Southern hybridization analysis revealed presence of reporter gene uidA in the genomic DNA samples from independent transgenic plants, confirming the integration of the transgene in recipient pear genomes. The stability of T-DNA integration was evaluated by the consistent presence of the Km selectable marker and the expression pattern of the introduced reporter gene uidA was analyzed by GUS histochemical assay.

Identification of phloem-associated translatome alterations during leaf development in Prunus domestica L.

“…S1). A. thaliana pSUC2 has been previously shown to be expressed specifically in phloem vascular tissues in many plant species including pear, lime, and sweet orange trees 32–34 , whereas A. thaliana pSULTR2;2 has been shown to be expressed in phloem vascular tissues in A. thaliana and Nicotiana benthamiana 15,35 . pSUC2 and pSULTR2;2 have also been shown to have slightly different expression patterns with pSUC2 driving expression predominately in shoot CCs, whereas pSULTR2;2 expresses in both shoot CCs and bundle sheath cells 15,35–38 .…”

In vitro regeneration of ‘carrick’ pear from leaf explants

“…(Table 1). Adventitious shoot regeneration from leaves of some pear varieties has been reported when TDZ (SUN et al, 2011, BELL et al, 2012 …”

Molecular cloning and heterologous expression analysis of JrVTE1 gene from walnut (Juglans regia)

“…Jujube and pear are important fruit crops with high commercial values (Nakajima et al 2013 ; Liu et al 2014 ). In this study, we successfully obtained the transgenic lines of jujube and pear using leaf as explants and employed the protocol of Sun et al ( 2011 ), and detected one or two copies of the transferred JrVTE1 gene in the representative transgenic lines of jujube and pear by gel blot (Fig. 3 ).…”

“…spinosa ) and pear ( P . communis ) cultivar ‘Old Home’ by the leaf transformation method described by Sun et al ( 2011 ). The calli of jujube and pear produced excisable shoots (2–3 mm) after a period of 7–8 months on selection medium.…”