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Sugita, R.

Publications and source records attributed to Sugita, R..

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Autophagy is induced during plant grafting for wound healing

O_LIGrafting is an important technique in agriculture to obtain several good traits such as high disease tolerance and high yield by exchanging root system. However, the underlined cellular processes to compensate the wound damage and repair tissues were largely unknown. C_LIO_LIWe analyzed two graft combinations: Nicotiana benthamiana (Nb) homograft as a compatible, wound repairing model and Nb heterograft with Arabidopsis thaliana (At) as an incompatible and more stressful model, which we recently identified as an exceptional maintainable interfamily grafting. C_LIO_LIIn both graft combinations, nutrient loss was observed in gene expression after grafting, where the level of nutrient loss was more sever in heterografts. Transmission electron micrographs of Nb/At heterografts suggested that microautophagy was induced in cells near the graft boundary. In At seedling micrografting, the fluorescence of autophagy protein marker GFP-ATG8 was highly observed at graft junction especially in cambial region. In At atg2 mutant homografts, growth after grafting decreased compared with wild-type homografts. Moreover, when NbATG5 knocked-down Nb scion was grafted to At stock, the successful rate of grafting was significantly decreased. C_LIO_LIAltogether, these results suggest that component of autophagy is induced during grafting and has a role in wound healing. C_LI

plant biology

ATP Binding Cassette Proteins ABCG37 and ABCG33 are required for potassium-independent cesium uptake in Arabidopsis roots

Radiocesium, accumulated in the soil by nuclear accidents is a major environmental concern. The transport process of cesium (Cs+) is tightly linked to the indispensable plant nutrient potassium (K+) as they both belong to the group I alkali metal with similar chemical properties. Most of the transporters that had been characterized to date as Cs+ transporters are directly or indirectly linked to K+. Using a combinatorial approach of physiology, genetics, cell biology and root uptake assay, here we identified two ATP-Binding Cassette (ABC) proteins, ABCG37 and ABCG33 as facilitators of Cs+ influx. The gain-of-function mutant of ABCG37 (abcg37-1) showed hypersensitive response to Cs+-induced root growth inhibition, while the double knock out mutant of ABCG33 and ABCG37 (abcg33-1abcg37-2) showed resistance. Single loss-of-function mutant of ABCG33 and ABCG37 did not show any alteration in Cs+ response. Short term uptake experiment with radioactive Cs+ revealed reduced Cs+ uptake in abcg33-1abgc37-2 compared with wild type in presence or absence of K+. Potassium response and content were unaffected in the double mutant background confirming that Cs+ uptake by ABCG33 and ABCG37 is independent of K+. Collectively, this work identified two ABC proteins as new Cs+ influx carriers, which act redundantly and independent of K+ uptake pathway.

plant biology