Imaging glutathione depletion in the rat brain using ascorbate derived hyperpolarized MR and PET probes Frontiers Endophytic fungus Serendipita indica accelerates ascorbate glutathione cycle of white clover in response to water stress Frontiers Redox homeostasis via gene families of ascorbate glutathione pathway Heat shock induces cross adaptation to aluminum stress through enhancing ascorbate glutathione cycle in wheat seedlings ScienceDirect