An Agrobacterium tumefaciens Strain with Gamma-Aminobutyric Acid Transaminase Activity Shows an Enhanced Genetic Transformation Ability in Plants

Abstract

Agrobacterium tumefaciens has the unique ability to mediate inter-kingdom DNA transfer, and for this reason, it has been utilized for plant genetic engineering. To increase the transformation frequency in plant genetic engineering, we focused on gamma-aminobutyric acid (GABA), which is a negative factor in the Agrobacterium-plant interaction. Recent studies have shown contradictory results regarding the effects of GABA on vir gene expression, leading to the speculation that GABA inhibits T-DNA transfer. In this study, we examined the effect of GABA on T-DNA transfer using a tomato line with a low GABA content. Compared with the control, the T-DNA transfer frequency was increased in the low-GABA tomato line, indicating that GABA inhibits T-DNA transfer. Therefore, we bred a new A. tumefaciens strain with GABA transaminase activity and the ability to degrade GABA. The A. tumefaciens strain exhibited increased T-DNA transfer in two tomato cultivars and Erianthus arundinacues and an increased frequency of stable transformation in tomato.

Third DWF1 paralog in Solanaceae, sterol Δ 24 -isomerase, branches withanolide biosynthesis from the general phytosterol pathway

“…Gene silencing was done using a tobacco rattle virus (TRV)-based VIGS system ( 61 ). Inserts were cloned into pTRV2 using EcoRI and KpnI restriction sites and the resulting plasmids cloned into Agrobacterium strain GV2260 transformed with GabT, provided by Satoko Nonaka, University of Tsukuba, Tsukuba, Japan ( 62 ). Phytoene desaturase (PDS) was used to verify VIGS and to determine time of harvest.…”

Characterizing the transport and utilization of the neurotransmitter GABA in the bacterial pathogen Brucella abortus

“…Mutating the GAD system in a plant, however, led to increased T-DNA transfer, a major virulence factor, from A . tumefaciens to a tomato plant model [ 15 , 16 ]. Alternatively, increasing GABA transaminase activity in A .…”

“…tumefaciens , causing a decrease in intracellular GABA concentrations, led to higher rates of T-DNA transfer and transformation of tomato plants, further emphasizing the inhibitory role of GABA in A . tumefaciens virulence [ 16 ].…”

Ecological Conditions and Molecular Determinants Involved in Agrobacterium Lifestyle in Tumors

“…Plant defense relies on signaling by chemical compounds such as salicylic acid (SA), jasmonic acid (JA), or ethylene that allow for the induction of pathogenesis-related proteins, some of which exhibit antimicrobial activities (Costet et al, 1999; Durrant and Dong, 2004). Even though plants initiate defense mechanisms against Agrobacterium (Deeken et al, 2006; Pitzschke, 2013; Shih et al, 2018), the bacterium is known to bypass those defenses to durably settle in tumors (Lee et al, 2009; Someya et al, 2013; Nonaka and Ezura, 2014; Nonaka et al, 2017). It should be emphasized that Agrobacterium is one of the only bacterial phytopathogens that exploits its host for niche construction instead of killing it (Leonard et al, 2017).…”