Isoprene emissions have been considered as a protective response of plants to heat stress, but there is limited information of how prolonged heat spells affect isoprene emission capacity, particularly under the drought conditions that often accompany hot weather. Under combined long-term stresses, presence of isoprene emission could contribute to the maintenance of the precursor pool for rapid synthesis of essential isoprenoids to repair damaged components of leaf photosynthetic apparatus. We studied changes in leaf isoprene emission rate, photosynthetic characteristics, and antioxidant enzyme activities in two hybrid Populus clones, Nanlin 1388 (relatively high drought tolerance) and Nanlin 895 (relatively high thermotolerance) that were subjected to long-term (30 d) soil water stress (25% versus 90% soil field capacity) combined with a natural heat spell (day-time temperatures of 35–40 °C) that affected both control and water-stressed plants. Unexpectedly, isoprene emissions from both the clones were similar and the overall effects of drought on the emission characteristics were initially minor; however, treatment effects and clonal differences increased with time. In particular, the isoprene emission rate only increased slightly in the Nanlin 895 control plants after 15 d of treatment, whereas it decreased by more than 5-fold in all treatment × clone combinations after 30 d. The reduction in isoprene emission rate was associated with a decrease in the pool size of the isoprene precursor dimethylallyl diphosphate in all cases at 30 d after the start of treatment. Net assimilation rate, stomatal conductance, the openness of PSII centers, and the effective quantum yield all decreased, and non-photochemical quenching and catalase activity increased in both control and water-stressed plants. Contrary to the hypothesis of protection of leaf photosynthetic apparatus by isoprene, the data collectively indicated that prolonged stress affected isoprene emissions more strongly than leaf photosynthetic characteristics. This primarily reflected the depletion of isoprene precursor pools under long-term severe stress.

Peas (Pisum sativum L.) serve as a vital model for plant development and stress research. The kinesin (KIN) gene family, encoding essential motor proteins, remains understudied in peas. Our research conducted a comprehensive genomic analysis of the KIN genes in peas, identifying 105 genes categorized into seven subfamilies based on evolutionary relationships, gene structures, conserved motifs, and interaction networks. A comparative analysis with Arabidopsis and soybean KIN gene families showed a non-uniform distribution of PsKIN genes across subfamilies. Homology analysis revealed that the PsKIN family has undergone segmental duplication and is under negative selection pressures, with conserved genes on chromosomes Ps5, Ps6, and Ps7 playing a significant role in pea evolution. Transcriptomics revealed 38 PsKIN genes with distinct tissue-specific expression, with PsKIN76, PsKIN96, PsKIN82, and PsKIN103 showing significant levels in roots, lateral roots, stems, petals, and seeds, respectively. Differential expression under drought and saline stress was observed, with PsKIN8, PsKIN11, PsKIN54 upregulated under drought, and PsKIN47 and PsKIN51 under saline stress. These genes are potential candidates for improving plant stress tolerance. This study offers insights into the pea KIN gene family, highlighting their potential in enhancing plant stress tolerance and setting a stage for future research.

This study focuses on the development and optimization of a water removal device for biogenic volatile organic compounds (BVOCs) from plant emissions. BVOCs play a crucial role in various ecological processes and have potential therapeutic effects on human health. However, it is challenging to accurately detect and analyze BVOCs due to their very low concentrations and interference by water vapor. This study systematically evaluates different filler materials and ratios to alleviate water vapor interference while maintaining BVOCs’ integrity. The experimental results demonstrate that the combination of MgSO₄ + Na₂SO₄ mixed filling and CuSO₄ layered filling in a 3:3:1 ratio can effectively improve the collection efficiency and detection accuracy of BVOCs. Meanwhile, the effectiveness of the device in improving the detection of volatile compounds in plant samples is also confirmed by the VOC verification experiments on Michelia maudiae and Cinnamomum camphora tree species after mechanical damage. The experimental results show that the device is effective in improving the detection of volatile compounds in plant samples. The findings provide a powerful technical means for exploring the role of BVOCs in environmental monitoring and scientific research.

This study aimed to explore the role of the trehalose-6-phosphate synthase (TPS) gene family in the adaptation of peas to environmental stress. A comprehensive analysis of the PsTPS gene family identified 20 genes with conserved domains and specific chromosomal locations. Phylogenetic analysis delineated evolutionary relationships, while gene structure analysis revealed compositional insights, and motif analysis provided functional insights. Cis-regulatory element identification predicted gene regulation patterns. Tissue-specific and stress-induced expression profiling highlighted eight genes with ubiquitous expression, with PsTPS15 and PsTPS18 displaying elevated expression levels in roots, nodules, and young stems, and PsTPS13 and PsTPS19 expression downregulated in seeds. Transcriptome analysis identified a differential expression of 20 PsTPS genes, highlighting the significance of 14 genes in response to drought and salinity stress. Notably, under drought conditions, the expression of PsTPS4 and PsTPS6 was initially upregulated and then downregulated, whereas that of PsTPS15 and PsTPS19 was downregulated. Salinity stress notably altered the expression of PsTPS4, PsTPS6, and PsTPS19. Taken together, these findings elucidate the regulatory mechanisms of the PsTPS gene family and their potential as genetic targets for enhancing crop stress tolerance.