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Dihydrogibberellin (DIH) is an eco‐friendly and low‐toxic regulator with immense potential for application in the current rice industry, specifically for increasing yield and lodging resistance. However, limited research has been conducted to explore the impact of DIH on the yield and lodging resistance of direct‐seeded rice (DSR, Oryza sativa L.). Therefore, a 2‐year field experiment was conducted to evaluate the effects of spraying different concentrations of 5% DIH emulsifiable concentrate on DSR during the tillering (1) and jointing (2) stages. Three concentrations of DIH were used: 27 (DIH27), 54 (DIH54), and 108 g ha−1 (DIH108). The commonly used paclobutrazol concentration in rice production (112.5 g ha−1) was compared and a clear water treatment was used as control (CK). The results of the experiment showed that the DIH treatments increased the DSR yield by 1.22%–22.64% and reduced lodging index by 8.9%–54.2% compared to the CK treatment. Additionally, the DIH treatments resulted in significant reductions in the length of the 1–3 basal internodes and plant height, as well as increases in the diameter and culm wall thickness of internodes. Moreover, the DIH treatments also led to higher dry matter percentages in stalks and leaf sheaths, as well as increased lignin and cellulose content. Furthermore, the best effect of DIH application was observed at the jointing stage in terms of increasing yield and lodging resistance. Therefore, this research demonstrates that the application of DIH to DSR at the jointing stage can be an effective strategy for increasing yield and improving lodging resistance. Core Ideas: Spraying dihydrogibberellin effectively improved the lodging resistance of direct‐seeded rice.Spraying dihydrogibberellin at jointing stage can significantly boost the lodging resistance of direct‐seeded rice.The lodging and rice grain yield effects of dihydrogibberellin and paclobutrazol are compared. [ABSTRACT FROM AUTHOR]

One of the most destructive diseases, Gibberella stalk rot (GSR), caused by Fusarium graminearum, reduces maize yields significantly. An induced resistance response is a potent and cost-effective plant defense against pathogen attack. The functional counterpart of JAs, coronatine (COR), has attracted a lot of interest recently due to its ability to control plant growth and stimulate secondary metabolism. Although several studies have focused on COR as a plant immune elicitor to improve plant resistance to pathogens, the effectiveness and underlying mechanisms of the suppressive ability against COR to F. graminearum in maize have been limited. We investigated the potential physiological and molecular mechanisms of COR in modulating maize resistance to F. graminearum. COR treatment strongly enhanced disease resistance and promoted stomatal closure with H2O2 accumulation, and 10 μg/mL was confirmed as the best concentration. COR treatment increased defense-related enzyme activity and decreased the malondialdehyde content with enhanced antioxidant enzyme activity. To identify candidate resistance genes and gain insight into the molecular mechanism of GSR resistance associated with COR, we integrated transcriptomic and metabolomic data to systemically explore the defense mechanisms of COR, and multiple hub genes were pinpointed using weighted gene correlation network analysis (WGCNA). We discovered 6 significant modules containing 10 candidate genes: WRKY transcription factor (LOC100279570), calcium-binding protein (LOC100382070), NBR1-like protein (LOC100275089), amino acid permease (LOC100382244), glutathione S-transferase (LOC541830), HXXXD-type acyl-transferase (LOC100191608), prolin-rich extensin-like receptor protein kinase (LOC100501564), AP2-like ethylene-responsive transcription factor (LOC100384380), basic leucine zipper (LOC100275351), and glycosyltransferase (LOC606486), which are highly correlated with the jasmonic acid–ethylene signaling pathway and antioxidants. In addition, a core set of metabolites, including alpha-linolenic acid metabolism and flavonoids biosynthesis linked to the hub genes, were identified. Taken together, our research revealed differentially expressed key genes and metabolites, as well as co-expression networks, associated with COR treatment of maize stems after F. graminearum infection. In addition, COR-treated maize had higher JA (JA-Ile and Me-JA) levels. We postulated that COR plays a positive role in maize resistance to F. graminearum by regulating antioxidant levels and the JA signaling pathway, and the flavonoid biosynthesis pathway is also involved in the resistance response against GSR. [ABSTRACT FROM AUTHOR]