“…Many studies found that signaling triggered by a moderate stress, such as Ca 2+ , ABA, H 2 O 2 , and NO signaling, is a common response of plants to abiotic and biotic stress, which in turn induces the acquisition of cross-adaptation. In addition, exogenously applied these signal molecules also can trigger corresponding signaling, followed by improving stress tolerance of plants, thus Ca 2+ , ABA, H 2 O 2 , and NO are considered to be candidate signal molecules in cross-adaptation in plants (Knight, 2000; Gong et al, 2001; Li and Gong, 2011; Li et al, 2012b; Fang H. et al, 2014; Qiao et al, 2015; Chen et al, 2016). More recently, many research groups found that a number of abiotic stresses also can trigger H 2 S signaling, while exogenously applied H 2 S can induce cross-adaptation to multiple stresses, indicating that H 2 S represents a potential candidate signal molecule in cross-adaptation in plants (Li, 2013; Lisjak et al, 2013; Calderwood and Kopriva, 2014; Hancock and Whiteman, 2014; Fotopoulos et al, 2015; Guo et al, 2016).…”