Banana and its close relative, plantain are globally important crops and there is considerable interest in optimizing their cultivation. Plantain has superior cold tolerance compared with banana and a thorough understanding of the molecular mechanisms and responses of plantain to cold stress has great potential value for developing cold tolerant banana cultivars. In this study, we used iTRAQbased comparative proteomic analysis to investigate the temporal responses of plantain to cold stress. Plantain seedlings were exposed for 0, 6, and 24 h of cold stress at 8°C and subsequently allowed to recover for 24 h at 28°C. A total of 3477 plantain proteins were identified, of which 809 showed differential expression from the three treatments. The majority of differentially expressed proteins were predicted to be involved in oxidation-reduction, including oxylipin biosynthesis, whereas others were associated with photosynthesis, photorespiration, and several primary metabolic processes, such as carbohydrate metabolic process and fatty acid beta-oxidation. Western blot analysis and enzyme activity assays were performed on seven differentially expressed, cold-response candidate plantain proteins to validate the proteomics data. Similar analyses of the seven candidate proteins were performed in cold-sensitive banana to examine possible functional conservation, and to compare the results to equivalent responses between the two species. Consistent results were achieved by Western blot and enzyme activity assays, demonstrating that the quantitative proteomics data collected in this study are reliable. Our results suggest that an increase of antioxidant capacity through adapted ROS scavenging capability, reduced production of ROS, and decreased lipid peroxidation contribute to molecular mechanisms for the increased cold tolerance in plantain. To the best of our knowledge, this is the first report of a global investigation on molecular responses of plantain to cold stress by proteomic analysis. Molecular & Cellular

et al. 2020. Fusaric acid instigates the invasion of banana by Fusarium oxysporum f. sp. cubense TR4. New Phytologist 225: 913-929.

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Potassium is one of the most essential inorganic cations for plant growth and development. The high a nity K + (HAK)/K + uptake (KUP)/K + transporter (KT) family plays essential roles in the regulation of cellular K + levels and the maintenance of osmotic balance. However, the roles of these genes in the responses of bananas to low-potassium stress are unclear. In this study, 24 HAK/KUP/KT (MaHAK) genes were identi ed from banana genomic data. These genes were further classi ed into four groups based on phylogenetic analysis, gene structure and conserved domain analysis. Segmental duplication events played an important role in the expansion of the MaHAK gene family. Transcriptome analysis revealed the expression patterns of MaHAKs in various tissues under different K + conditions. MaHAK14b was upregulated under both short-and long-term K + -de cient conditions, suggesting that it plays crucial roles in K + uptake at low K + concentrations. Furthermore, MaHAK14b mediated K + uptake when it was heterologously expressed in the yeast mutant R5421 on low K + medium. Collectively, these ndings provide a foundation for further functional analysis of MaHAK genes, which may be used to improve stress resistance in bananas.