Comparative transcriptome analysis between uninfected wild-type and Atseor1ko A. thaliana

It is beyond doubt that sieve element occlusion (SEO) proteins orderly framed in so-called forisomes are responsible for the sieve-plate occlusion in legumes. By contrast, it is a matter of debate, if SEOR1 and SEOR2 in a loosely filamentous shape, as in the sieve tubes of Arabidopsis and in other dicots, are capable of a similar occlusion achievement. The clogging probably requires a specific Ca2+-mediated conjugation of both AtSEOR fibrillar species and is regarded as a fast and efficient strategy to impair phloem translocation.Detached from AtSEOR1, AtSEOR2 may perform a function other than sieve-pore occlusion in view of the decreased pathogen titers in phytoplasma-infected Atseor1ko plants. Suppression of phytoplasma proliferation suggests that SEOR2 strengthens in some way plant immune processes from the early stage of infection on. Moreover, the capability of AtSEOR2 to interact with several proteins involved in pathogen perception and in associated defence responses has recently been underscored. As a matter of fact, AtSEOR2, detached from AtSEOR1, interacts with plant resistance proteins in yeast-two hybrid assays. This all suggests that AtSEOR2 acts in the defense cascade during phytoplasma infection.The intriguing potential of AtSEOR2 called for further investigations on the molecular traits of the Atseor1ko line to unveil details of the involvement of SEOR2 in defence responses to CY phytoplasmas. Therefore, a comparative RNA-seq analysis between uninfected wild-type and Atseor1ko A. thaliana plants was conducted.