Survey and Genetic Identification of Zucchini Yellow Mosaic Virus, Watermelon Mosaic Virus, and Melon Necrotic Spot Virus Infecting Watermelon and Muskmelon in South Korea A-Ram Jeong, Hyunji Lee, Oh-Kyu Kwon, Gung Pyo Lee, Ryoung Shin, et al. Research in Plant Disease, 2024 Watermelon (Citrullus lanatus) and muskmelon (Cucumis melo), both members of the Cucurbitaceae, are economically important fruit crops in Korea. Various viruses cause major diseases, significantly reducing their production. In this study, we investigated the incidence of zucchini yellow mosaic virus (ZYMV), watermelon mosaic virus (WMV), and melon necrotic spot virus (MNSV) by collecting symptomatic watermelon and muskmelon leaves from nine cities (65 fields) across Korea between 2019 and 2023. At least one of the viruses was detected in 125 samples, with ZYMV, WMV, and MNSV identified in 74, 27, and 52 samples, respectively. Most ZYMV and WMV isolates were classified as subgroup III of ZYMV group A and subgroup I of WMV group A, respectively. MNSV isolates were clustered into two distinct groups: the muskmelon group and the watermelon group. This report will help farmers develop effective viral disease management strategies for watermelon and muskmelon crops in Korea.
Reduced Tomato Bacterial Wilt by Ferrous Chloride Application Hyeon Ji Kim, Su Min Kim, Yeon Hwa Kim, Jeong Hoon Park, Dong Ki Kang, et al. Research in Plant Disease, 2023 Exogenous ferrous chloride (FeCl<sub>2</sub>) suppressed in vitro growth of Ralstonia pseudosolanacearum, causing bacteria for tomato bacterial wilt. More than 50 μM of FeCl<sub>2</sub> reduced the in vitro bacterial growth in dosedependent manners. Two to 200 μM of FeCl<sub>2</sub> did not affect the fresh weight of detached tomato leaves at 3 and 5 days after the petiole dipping without the bacterial inoculation. The bacterial wilt of the detached tomato leaves was evaluated by inoculating two different inoculum densities of R. pseudosolanacearum (10<sup>5</sup> and 10<sup>7</sup> cfu/ml) in the presence of FeCl<sub>2</sub>. Bacterial wilt in the detached leaves by 10<sup>5</sup> cfu/ml was efficiently attenuated by 10–200 μM of FeCl<sub>2</sub> at 3 and 5 days post-inoculation (dpi), but bacterial wilt by 10<sup>7</sup> cfu/ml was only reduced by 200 μM of FeCl<sub>2</sub> at 3 and 5 dpi. These results suggest that iron nutrients can be included in the integrated disease management of tomato bacterial wilt.
Calcium channels and transporters: Roles in response to biotic and abiotic stresses Chang-Jin Park, Ryoung Shin Frontiers in Plant Science, 2022 Calcium (Ca2+) serves as a ubiquitous second messenger by mediating various signaling pathways and responding to numerous environmental conditions in eukaryotes. Therefore, plant cells have developed complex mechanisms of Ca2+ communication across the membrane, receiving the message from their surroundings and transducing the information into cells and organelles. A wide range of biotic and abiotic stresses cause the increase in [Ca2+]cyt as a result of the Ca2+ influx permitted by membrane-localized Ca2+ permeable cation channels such as CYCLIC NUCLEOTIDE-GATE CHANNELs (CNGCs), and voltage-dependent HYPERPOLARIZATION-ACTIVATED CALCIUM2+ PERMEABLE CHANNELs (HACCs), as well as GLUTAMATE RECEPTOR-LIKE RECEPTORs (GLRs) and TWO-PORE CHANNELs (TPCs). Recently, resistosomes formed by some NUCLEOTIDE-BINDING LEUCINE-RICH REPEAT RECEPTORs (NLRs) are also proposed as a new type of Ca2+ permeable cation channels. On the contrary, some Ca2+ transporting membrane proteins, mainly Ca2+-ATPase and Ca2+/H+ exchangers, are involved in Ca2+ efflux for removal of the excessive [Ca2+]cyt in order to maintain the Ca2+ homeostasis in cells. The Ca2+ efflux mechanisms mediate the wide ranges of cellular activities responding to external and internal stimuli. In this review, we will summarize and discuss the recent discoveries of various membrane proteins involved in Ca2+ influx and efflux which play an essential role in fine-tuning the processing of information for plant responses to abiotic and biotic stresses.
