Elevated temperatures limit plant growth and reproduction and pose a growing threat to agriculture. Plant heat stress response is highly conserved and fine-tuned in multiple pathways. Spinach (Spinacia oleracea L.) is a cold tolerant but heat sensitive green leafy vegetable. In this study, heat adaptation mechanisms in a spinach sibling inbred heat-tolerant line Sp75 were investigated using physiological, proteomic, and phosphoproteomic approaches. The abundance patterns of 911 heat stress-responsive proteins, and phosphorylation level changes of 45 phosphoproteins indicated heat-induced calcium-mediated signaling, ROS homeostasis, endomembrane trafficking, and cross-membrane transport pathways, as well as more than 15 transcription regulation factors. Although photosynthesis was inhibited, diverse primary and secondary metabolic pathways were employed for defense against heat stress, such as glycolysis, pentose phosphate pathway, amino acid metabolism, fatty acid metabolism, nucleotide metabolism, vitamin metabolism, and isoprenoid biosynthesis. These data constitute a heat stress-responsive metabolic atlas in spinach, which will springboard further investigations into the sophisticated molecular mechanisms of plant heat adaptation and inform spinach molecular breeding initiatives.

Climate change has resulted in major changes in plant phenology across the globe that includes leaf‐out date and flowering time. The ability of species to respond to climate change, in part, depends on their response to climate as a phenological cue in general. Species that are not phenologically responsive may suffer in the face of continued climate change. Comparative studies of phenology have found phylogeny to be a reliable predictor of mean leaf‐out date and flowering time at both the local and global scales. This is less true for flowering time response (i.e., the correlation between phenological timing and climate factors), while no study to date has explored whether the response of leaf‐out date to climate factors exhibits phylogenetic signal. We used a 52‐year observational phenological dataset for 52 woody species from the Forest Botanical Garden of Heilongjiang Province, China, to test phylogenetic signal in leaf‐out date and flowering time, as well as, the response of these two phenological traits to both temperature and winter precipitation. Leaf‐out date and flowering time were significantly responsive to temperature for most species, advancing, on average, 3.11 and 2.87 day/°C, respectively. Both leaf‐out and flowering, and their responses to temperature exhibited significant phylogenetic signals. The response of leaf‐out date to precipitation exhibited no phylogenetic signal, while flowering time response to precipitation did. Native species tended to have a weaker flowering response to temperature than non‐native species. Earlier leaf‐out species tended to have a greater response to winter precipitation. This study is the first to assess phylogenetic signal of leaf‐out response to climate change, which suggests, that climate change has the potential to shape the plant communities, not only through flowering sensitivity, but also through leaf‐out sensitivity.

The efficacy of traditional control measures for the management of plant pathogens is decreasing, and the resistance of these pathogens to pesticides is increasing, which poses a serious threat to global food security. The exploration of novel and efficient management measures to combat plant disease is an urgent need at this time. In this study, fungal metabolites from three Trichoderma spp. (T. harzianum, T. virens and T. koningii) were prepared on three different growth media (STP, MOF and supermalt (SuM)). The fungal metabolites were tested in vitro and in vivo from March–April 2020 under greenhouse conditions in a pot experiment utilizing completely randomized design to test their management of the bacterial wilt disease caused by R. solanacearum in tomato plants. The effect of the fungal metabolites on bacterial cell morphology was also investigated through scanning electron microscopy (SEM) analysis. In vitro investigation showed that the fungal metabolites of T. harzianum obtained on the STP medium were the most effective in inhibiting in vitro bacterial growth and produced a 17.6 mm growth inhibition zone. SEM analysis confirms the rupture of the cell walls and cell membranes of the bacterium, along with the leakage of its cell contents. Generally, fungal metabolites obtained on an STP medium showed higher activity than those obtained on the other two media, and these metabolites were then evaluated in vivo according to three application times (0 days before transplantation (DBT), 4 DBT and 8 DBT) in a greenhouse trial to examine their ability to manage R. solanacearum in tomato plants. Consistent with in vitro results, the results from the greenhouse studies showed a level of higher anti-bacterial activity of T. harzianum metabolites than they did for the metabolites of other fungi, while among the three application times, the longest time (8 DBT) was more effective in controlling bacterial wilt disease in tomato plants. Metabolites of T. harzianum applied at 8 DBT caused the maximum decrease in soil bacterial population (1.526 log cfu/g), resulting in the lowest level of disease severity (area under disease progressive curve (AUDPC) value: 400), and maximum plant freshness (with a resulting biomass of 36.7 g, a root length of 18.3 cm and a plant height of 33.0 cm). It can be concluded that T. harzianum metabolites obtained on an STP medium, when applied after 8 DBT, can suppress soil bacterial population and enhance plant growth, and thus can be used as a safe, environmentally-conscious and consumer-friendly approach to managing bacterial wilt disease in tomato plants and possibly other crops.

To explore the optimum conditions for the extraction of anthocyanins and flavonols from bog bilberry (Vaccinium uliginosum L.) marc on a single-factor experimental basis, a response surface methodology was adopted for this intensive study. The extraction procedure was carried out in a Waring blender and followed an ultrasonic bath, and the natural antioxidant carnosic acid was added to inhibit oxidation. The optimum extraction conditions were as follows: a volume fraction of ethanol of 70%, an antioxidant content of 0.02% (the mass of sample) carnosic acid, a liquid–solid ratio of 16 mL/g, a homogenization time of 3 min, a reaction temperature of 55 °C, an ultrasound irradiation frequency of 80 kHz, an ultrasound irradiation power of 200 W, and an ultrasound irradiation time of 40 min. Satisfactory yields of anthocyanins (13.95 ± 0.37 mg/g) and flavonols (3.51 ± 0.16 mg/g) were obtained. The experimental results showed that the carnosic acid played an effective antioxidant role in the extraction process of anthocyanins and flavonols with a green and safety guarantee.

Understory vegetation hosts high biodiversity and plays a critical role in the ecosystem processes of boreal forests. However, the drivers of understory plant diversity in this high-latitude ecosystem remain uncertain. To investigate the influences of forest type and latitude on understory beta diversity at different scales, we quantified the species composition of Vaccinium uliginosum Linnaeus communities under broadleaf and coniferous forests at two latitudes at the quadrat (2 × 2 m) and plot (10 × 10 m) scales in the Greater Xing’an Mountains, NE China. At the quadrat scale, species alpha diversity of V. uliginosum communities was higher in broadleaf forests than that in coniferous forests at both latitudes. The differences in species beta diversity (the Sørensen’s dissimilarity) in two forest types depended on the latitude: beta diversity in broadleaf forests was higher than that in coniferous forests at the higher latitude, while beta diversity in coniferous forests was higher at the lower latitude. At the plot scale, alpha and beta diversity of V. uliginosum communities decreased from broadleaf forests to coniferous forests at the higher latitude, and they did not show significant differences between forest types at the lower latitude. These results indicate the interactive effects of forest type and latitude on beta diversity of understory vegetation. Moreover, the influences of forest type and latitude on species alpha and beta diversity were different across the two spatial scales, suggesting that the assembly mechanisms underlying species diversity may be different at different scales. Understanding the maintenance of understory vegetation diversity will benefit the conservation and management of boreal forests.