Citation: Lv, L.; Luo, J.; Ahmed, T.; Zaki, H.E.M.; Tian, Y.; Shahid, M.S.; Chen, J.; Li, B. Beneficial Effect and Potential Risk of Pantoea on Rice Production. Plants 2022, 11, 2608. https://doi.org/10.3390/ plants11192608 Academic Editor: Tika Adhikari Received: 24 August 2022 Accepted: 29 September 2022 Published: 4 October 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). plants Review Beneficial Effect and Potential Risk of Pantoea on Rice Production Luqiong Lv 1,† , Jinyan Luo 2,† , Temoor Ahmed 1 , Haitham E. M. Zaki 3,4 , Ye Tian 1 , Muhammad Shafiq Shahid 5 , Jianping Chen 6, * and Bin Li 1, * 1 State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of ZhejiangProvince, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China 2 Department of Plant Quarantine, Shanghai Extension and Service Center of Agriculture Technology, Shanghai 201103, China 3 Horticulture Department, Faculty of Agriculture, Minia University, El-Minia 61517, Egypt 4 Applied Biotechnology Department, University of Technology and Applied Sciences-Sur, Sur 411, Oman 5 Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al-khod 123, Oman 6 State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Virology, Ningbo University, Ningbo 315211, China * Correspondence: jpchen2001@126.com (J.C.); libin0571@zju.edu.cn (B.L.); Tel.: +86-571-8898-2412 (B.L.) † These authors contributed equally to this work. Abstract: Bacteria from the genus Pantoea have been reported to be widely distributed in rice paddy environments with contradictory roles. Some strains promoted rice growth and protected rice from pathogen infection or abiotic stress, but other strain exhibited virulence to rice, even causing severe rice disease. In order to effectively utilize Pantoea in rice production, this paper analyzed the mechanisms underlying beneficial and harmful effects of Pantoea on rice growth. The beneficial effect of Pantoea on rice plants includes growth promotion, abiotic alleviation and disease inhibition. The growth promotion may be mainly attributed to nitrogen-fixation, phosphate solubilization, plant physiological change, the biosynthesis of siderophores, exopolysaccharides, 1-aminocyclopropane- 1-carboxylic acid deaminase and phytohormones, including cytokinin, indole-3-acetic acid (IAA), auxins, abscisic acid and gibberellic acid, while the disease inhibition may be mainly due to the induced resistance, nutrient and spatial competition, as well as the production of a variety of antibiotics. The pathogenic mechanism of Pantoea can be mainly attributed to bacterial motility, production of phytohormones such as IAA, quorum sensing-related signal molecules and a series of cell wall-degrading enzymes, while the pathogenicity-related genes of Pantoea include genes encoding plasmids, such as the pPATH plasmid, the hypersensitive response and pathogenicity system, as well as various types of secretion systems, such as T3SS and T6SS. In addition, the existing scientific problems in this field were discussed and future research prospects were proposed. Keywords: disease; Pantoea; PGPR; rice; stress resilience 1. Introduction The Pantoea is a ubiquitous bacteria with a high degree of diversity and a variety of lifestyles, such as pathogen, epiphyte, endophyte and saprophytic, which has been often isolated from various geographical ecological niches and hosts, such as animals, humans and plants as well as some other environmental systems such as water and soil [1,2]. Indeed, the bacterial genus Pantoea is characterized by its functional versatility, environmental ubiquity and genetic similarity, and since the establishment of the genus with the type species Pantoea agglomerans, the ranks of the Pantoea genus have been strengthened by a large number of new species, which originated from a wide range of environments [3]. Nowadays, Pantoea is composed of 25 phenotypically similar species [4]. Plants 2022, 11, 2608. https://doi.org/10.3390/plants11192608 https://www.mdpi.com/journal/plants