Sweet potato, commonly planted in Southeast Asia and South America with abundant rainfall, often suffers from waterlogging. The aerenchyma formation in roots is an effective way for plants to facilitate gas exchange. In the present study, tolerant and sensitive varieties, respectively, designated NC1 and C211, were evaluated under water oxygen content at 2.0 mg·L−1 (hypoxia treatment) and 8.0 mg·L−1 (control). The results showed that NC1 variety has a relatively higher root growth rate under low oxygen condition. In NC1 plants, aerenchyma was observed in the mid‐section of the main adventitious root and spread to the proximal and distal ends, forming a complete channel in the cortex. However, in C211 plants, the aerenchyma occurred relatively later and could not turn into a whole channel. Ethylene synthesis‐related (ACS1, ACS4, ACS5, etc.) and signal transduction‐related (ETR1, ERS1, EIN2, etc.) genes were upregulated in the NC1 plants and led to changes in the reactive oxygen species‐related genes (RBOHA, SOD, CAT, etc.) and enzyme activities. It was found that programmed cell death was induced by H2O2 accumulation. A regulatory model of lysigenous aerenchyma formation in the root of sweet potato was constructed. Our study enriches the understanding of the mechanisms of the aerenchyma formation in plants.

Sweet potato (Ipomoea batatas L.) is considered a highly nutritional and economical crop due to its high contents of bioactive substances, such as anthocyanin and chlorogenic acid (CGA), especially in leaves and stems. The roles of noncoding RNAs (ncRNA), including long noncoding RNA (lncRNA) and microRNA (miRNA), in CGA synthesis, are still unknown. In this study, the differentially expressed (DE) mRNAs, miRNAs, and lncRNAs in two leafy vegetable genotypes “FS7‐6‐14‐7” (high CGA content) and “FS7‐6” (low CGA content) were identified. The cis‐regulation between lncRNA and mRNA was analyzed. Then, the CGA synthesis‐related modules MEBlue and MEYellow were identified to detect trans‐regulation mRNA‐lncRNA pairs. The GO and KEGG annotations suggested that mRNA in these two modules was significantly enriched in the secondary metabolite synthesis biosynthesis category. A competing endogenous RNAs (ceRNA) network, including 8730 miRNA‐mRNA and 444 miRNA‐lncRNA pairs, was constructed by DEmiRNA target prediction. Then, a CGA synthesis‐related ceRNA network was obtained with lncRNA and mRNA from MEBlue and MEYellow. Finally, one relational pair, MSTRG.47662.1/mes‐miR398/itb04g00990, was selected for functional validation. Overexpression of lncRNA MSTRG.47662.1 and mRNA itb04g00990 increased CGA content in both tobacco and sweet potato callus, while overexpression of miRNA mes‐miR398 decreased CGA content. Meanwhile, regression analysis of the expression patterns demonstrated that MSTRG.47662.1, acting as a ceRNA, promoted itb04g00990 expression by competitively binding mes‐miR398 in CGA synthesis in sweet potato. Our results provide insights into how ncRNA‐mediated ceRNA regulatory networks likely contribute to CGA synthesis in leafy sweet potato.

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<abstract> <p>Beneficial endophytic bacteria influence their host plant to grow and resist pathogens. Despite the advantages of endophytic bacteria to their host, their application in agriculture has been low. Furthermore, many plant growers improperly use synthetic chemicals due to having no or little knowledge of the role of endophytic bacteria in plant growth, the prevention and control of pathogens and poor access to endobacterial bioproducts. These synthetic chemicals have caused soil infertility, environmental contamination, disruption to ecological cycles and the emergence of resistant pests and pathogens. There is more that needs to be done to explore alternative ways of achieving sustainable plant production while maintaining environmental health. In recent years, the use of beneficial endophytic bacteria has been noted to be a promising tool in promoting plant growth and the biocontrol of pathogens. Therefore, this review discusses the roles of endophytic bacteria in plant growth and the biocontrol of plant pathogens. Several mechanisms that endophytic bacteria use to alleviate plant biotic and abiotic stresses by helping their host plants acquire nutrients, enhance plant growth and development and suppress pathogens are explained. The review also indicates that there is a gap between research and general field applications of endophytic bacteria and suggests a need for collaborative efforts between growers at all levels. Furthermore, the presence of scientific and regulatory frameworks that promote advanced biotechnological tools and bioinoculants represents major opportunities in the applications of endophytic bacteria. The review provides a basis for future research in areas related to understanding the interactions between plants and beneficial endophytic microorganisms, especially bacteria.</p> </abstract>

The soil inhabits many microbes, including plant parasitic nematodes. Plant parasitic nematodes are reported to cause substantial damage to crops which results in yield and economic losses. Chemical control is the most widely used method to control plant parasitic nematodes. However, the consequences of synthetic chemicals are detrimental to human health, animals, and the environment and face so many strict regulatory measures. Synthetic chemicals are also not reliable with their inability to provide long-term protection. Many studies have shown that the use of beneficial fungi and bacteria has the potential to prevent and suppress plant parasitic nematodes while keeping the environment safe. Several experiments have demonstrated that bioproducts of microbial origin are cheap, safe, and provide long-lasting biocontrol effects against pathogens both in vitro and field conditions. Therefore, this review aims to discuss mechanisms that beneficial microbes and their products use to successfully suppress plant parasitic nematodes. The review also explains the importance of using commercial bionematicides in the sustainable management of plant parasitic nematodes. The existing challenges that are limiting the full application of beneficial microbes, and what needs to be done to fully utilize biocontrol agents in the management of plant parasitic nematodes have also been discussed. To the best of our knowledge, this review has come at the right time to give researchers and plant growers more options when several synthetic chemical nematicides are being banned by regulatory authorities due to their hazardous effects.