Thermospermine catabolism increases Arabidopsis thaliana resistance to Pseudomonas viridiflava

Abstract

This work investigated the roles of the tetraamine thermospermine (TSpm) by analysing its contribution to Arabidopsis basal defence against the biotrophic bacterium Pseudomonas viridiflava. The participation of polyamine oxidases (PAOs) in TSpm homeostasis and TSpm-mediated defence was also investigated. Exogenous supply of TSpm, as well as ectopic expression of the TSpm biosynthetic gene ACL5, increased Arabidopsis Col-0 resistance to P. viridiflava, while null acl5 mutants were less resistant than Col-0 plants. The above-mentioned increase in resistance was blocked by the PAO inhibitor SL-11061, thus demonstrating the participation of TSpm oxidation. Analysis of PAO genes expression in transgenic 35S::ACL5 and Col-0 plants supplied with TSpm suggests that PAO 1, 3, and 5 are the main PAOs involved in TSpm catabolism. In summary, TSpm exhibited the potential to perform defensive functions previously reported for its structural isomer Spm, and the relevance of these findings is discussed in the context of ACL5 expression and TSpm concentration in planta. Moreover, this work demonstrates that manipulation of TSpm metabolism modifies plant resistance to pathogens.

Cotton ACAULIS5 is involved in stem elongation and the plant defense response to Verticillium dahliae through thermospermine alteration

“…Moreover, AtACL5 overexpression in Col-0 plants under the control of the CaMV35S promoter failed to increase T-Spm biosynthesis in planta, and exhibited a normal phenotype of plant height, despite up to 43-fold higher transcript levels of AtACL5 (Marina et al 2013). Also Put, Spd, and Spm dis not change in those transgenic lines compared with Col-0 plants (Marina et al 2013). Nevertheless, we noted here that ectopic expression of a heterogenous GhACL5 gene was positively associated with elevated levels of endogenous T-Spm and taller plants.…”

“…Moreover, excess applications of exogenous T-Spm inhibited leaf expansion in both WT and acl5-1 seedlings (Kakehi et al 2008). Moreover, AtACL5 overexpression in Col-0 plants under the control of the CaMV35S promoter failed to increase T-Spm biosynthesis in planta, and exhibited a normal phenotype of plant height, despite up to 43-fold higher transcript levels of AtACL5 (Marina et al 2013). Also Put, Spd, and Spm dis not change in those transgenic lines compared with Col-0 plants (Marina et al 2013).…”

“…It is required for stem elongation in Arabidopsis (Kakehi et al 2008), and its catabolism increases Arabidopsis resistance to Pseudomonas viridiflava (Marina et al 2013). In Arabidopsis inactivation of AtACL5 gene causes a defect in the elongation of stem internodes by reducing cell expansion (Hanzawa et al 2000), also controls Arabidopsis xylem specification by preventing premature cell death (Muñiz et al 2008).…”

Evaluasi Resistensi Progeni Anggrek Phalaenopsis terhadap Penyakit Busuk Lunak (Pseudomonas viridiflava)

“…Mekanisme ketahanan tanaman terhadap P. viridiflava hingga saat ini belum terungkap sempurna. Marina et al (2013) melaporkan tingkat resistensi tanaman terhadap infeksi P. viridiflava berhubungan dengan meningkatnya konsentrasi poliamine dalam tubuh tanaman. Rossi et al (2015) juga mengemukakan aktivitas enzim arginine dekarbosilase dapat menghambat patogen P. viridiflava.…”

The Role of Polyamines in Plant Disease Resistance

“…Arabidopsis plants increased resistance to Pseudomonas viridiflava (Marina et al, 2013). The authors suggested that T-Spm oxidation is crucial for eliciting plant resistance.…”