*Review* **Crosstalk between Hydrogen Sulfide and OtherSignal Molecules Regulates Plant Growth and Development**

#### **Lijuan Xuan** †**, Jian Li** †**, Xinyu Wang and Chongying Wang \***

Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China; xuanlj17@lzu.edu.cn (L.X.); Lijian18@lzu.edu.cn (J.L.); wangxy@lzu.edu.cn (X.W.)

**\*** Correspondence: wangcy@lzu.edu.cn; Tel./Fax: +86-093-1891-4155

† These authors contributed equally to this work.

Received: 31 May 2020; Accepted: 24 June 2020; Published: 28 June 2020

**Abstract:** Hydrogen sulfide (H2S), once recognized only as a poisonous gas, is now considered the third endogenous gaseous transmitter, along with nitric oxide (NO) and carbon monoxide (CO). Multiple lines of emerging evidence sugges<sup>t</sup> that H2S plays positive roles in plant growth and development when at appropriate concentrations, including seed germination, root development, photosynthesis, stomatal movement, and organ abscission under both normal and stress conditions. H2S influences these processes by altering gene expression and enzyme activities, as well as regulating the contents of some secondary metabolites. In its regulatory roles, H2S always interacts with either plant hormones, other gasotransmitters, or ionic signals, such as abscisic acid (ABA), ethylene, auxin, CO, NO, and Ca2+. Remarkably, H2S also contributes to the post-translational modification of proteins to affect protein activities, structures, and sub-cellular localization. Here, we review the functions of H2S at different stages of plant development, focusing on the S-sulfhydration of proteins mediated by H2S and the crosstalk between H2S and other signaling molecules.

**Keywords:** hydrogen sulfide; reactive oxygen species; S-sulfhydration; plant hormone; gasotransmitter
