Mark Christian Felipe R. Redillas

Legumes are among the most important crops globally, serving as a major food source for protein and oil. In tropical regions, the cultivation of legumes has expanded significantly due to the increasing demand for food, plant-based products, and sustainable agriculture practices. However, tropical environments pose unique challenges, including high temperatures, erratic rainfall, soil infertility, and a high incidence of pests and diseases. Indeed, legumes are vulnerable to infections caused by bacteria, fungi, oomycetes, viruses, and nematodes. This review highlights the importance of legumes in tropical farming and discusses major diseases affecting productivity and their impact on the economy, environment, and lives of smallholder legume farmers. We emphasize the use of legume genetic resources and breeding, and biotechnology innovations to foster resistance and address the challenges posed by pathogens in legumes. However, an integrated approach that includes other cultivation techniques (e.g., crop rotation, rational fertilization, deep plowing) remains important for the prevention and control of diseases in legume crops. Finally, we highlight the contributions of plant genetic resources to smallholder resilience and food security.

Oxidative stress, arising from environmental challenges such as drought, salinity, extreme temperatures, and pathogen attack, significantly impairs rice (Oryza sativa) growth, yield, and grain quality. This review provides a comprehensive synthesis of the mechanisms underlying oxidative stress in rice, with a focus on the generation of reactive oxygen species (ROS), their physiological and molecular impacts, and the antioxidant defense systems employed for mitigation. The roles of enzymatic and non-enzymatic antioxidants, along with key transcription factors, signaling pathways, and stress-responsive genes, are explored in detail. This study further highlights varietal differences in oxidative stress tolerance, emphasizing traditional, modern, and genetically engineered rice cultivars. Recent advances in breeding strategies, gene editing technologies, and multi-omics integration are discussed as promising approaches for enhancing stress resilience. The regulatory influence of epigenetic modifications and small RNAs in modulating oxidative stress responses is also examined. Finally, this paper identifies critical research gaps—including the need for multi-stress tolerance, long-term field validation, and deeper insights into non-coding RNA functions—and offers recommendations to inform the development of climate-resilient rice varieties through integrative, sustainable strategies.

Soil contamination, including in rice fields, arises from a variety of natural processes and anthropogenic activities, leading to an accumulation of heavy metals. While extensive research has addressed the bioaccumulation of heavy metals in rice, only limited systematic reviews have examined their specific impact on the morpho-physiological traits of rice plants. This review aims to provide a comprehensive synthesis of current studies detailing the rice cultivars, types of heavy metals investigated, study designs, sampling locations, and experimental sites while systematically analyzing the morphological and physiological responses of rice cultivars to heavy metal stress. Studies show that morphological traits generally exhibit a decline under heavy metal exposure. Physiologically, rice cultivars tend to show decreased total chlorophyll and carotenoid levels, along with increased levels of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and proline. These findings suggest that plant genotype, type of heavy metal, and intensity of stress significantly modulate the morphological and physiological responses of rice, highlighting critical areas for further research in heavy metal stress tolerance in rice cultivars.

Plants accumulate several metabolites in response to drought stress, including branched-chain amino acids (BCAAs). However, the roles of BCAAs in plant drought responses and the underlying molecular mechanisms for BCAA accumulation remain elusive. Here, we demonstrate that rice (Oryza sativa) DROUGHT-INDUCED BRANCHED-CHAIN AMINO ACID AMINOTRANSFERASE (OsDIAT) mediates the accumulation of BCAAs in rice in response to drought stress. An in vitro enzyme activity assay indicated that OsDIAT is a branched-chain amino acid aminotransferase, and subcellular localization analysis revealed that OsDIAT localizes to the cytoplasm. The expression of OsDIAT was induced in plants upon exposure to abiotic stress. OsDIAT-overexpressing (OsDIAT^OX) plants were more tolerant to drought stress, whereas osdiat plants were more susceptible to drought stress compared with nontransgenic (NT) plants. Amino acid analysis revealed that BCAA levels were higher in OsDIAT^OX but lower in osdiat compared with in NT plants. Finally, the exogenous application of BCAAs improved plant tolerance to osmotic stress compared with that in control plants. Collectively, these findings suggest that OsDIAT mediates drought tolerance by promoting the accumulation of BCAAs.

Urban stormwater has become a persistent concern on a global scale due to its adverse environmental implications. It is the prime vector of aquatic contaminants worldwide that causes pollutants when water bodies drain. Bioretention systems are increasingly used to alleviate setbacks associated with stormwater run-off in urban locales. It has played a substantial role in the implementation of low impact development (LID), a concept that addresses urban stormwater problems caused by land changes and development. The use of LID technologies is an innovative approach. However, it is beset with challenges, such as the insufficiency of data on rainfall distribution and difficulty in interpreting data. To address these research gaps, the present study developed a fuzzy rough set data algorithm for bioretention systems. Event mean concentration calculations and fuzzification of rainfall were performed to produce a rough set-based decision rule. Using the Weibull probability distribution, fuzzification of rainfall and parameter data, rule induction, and Preece testing, bioretention design considerations were determined. The bioretention characterizations generated evident pollutants present in the catch basin before and after filtration. In addition, the bioretention characterization conducted in this study was able to reduce the number of tests needed for rainfall identification based on the different attributes.

Summary: Emission of volatile organic compounds (VOCs) in plants is triggered by several biotic and abiotic factors, such as nutrient deficiency, environmental stress, and pathogenic attacks. For instance, plants suffering from limited or excessive nitrogen (N) supply may experience internal stress which can ultimately lower their stability and immunity making them susceptible to infection and infestation. In this study, VOCs from Capsicum annuum var. longum (Solanaceae) exposed to nitrogen (1.8 g/L, 4.5 g/L, and 9 g/L urea) were extracted using a 100 μm Solid Phase Microextraction (SPME) fiber coated with polydimethylsiloxane (PDMS). Using Gas Chromatography-Mass Spectrometry (GC-MS), extracted VOCs from N-treated plants were identified as Butanoic acid, 3-hexenyl ester, (E)-; Butanoic acid, hexyl ester; Hexanoic acid, 3-hexenyl ester, (Z)-; Hexanoic acid, 4-hexen-1-yl ester; cis-3-Hexenyl cis-3-hexenoate and 4-Pentenoic acid 2-methyl-, hexyl ester. Among these volatiles, butanoic acid, 3-hexenyl ester showed the most distinctive peak from the N-treated plants in comparison with the untreated. In addition, the Green Leaf Volatiles (GLV) 3-Hexenal; 2-Hexenal; 3-Hexen-1-ol, (Z)-; 2-Hexen-1-ol, (E) and 1-Hexanol were also detected from the N-treated plants. The identification of plant volatiles provides useful information that can be used in agricultural practices and plant phenotyping.