Plant signaling & behavior最新文献

Alternating magnetic fields (MF) with Schumann resonance frequencies accompanied the development of living organisms throughout evolution, but today it remains unclear whether they can have a special biological effect in comparison with surrounding non-resonant frequencies. This work shows some stimulating effect of extremely low-frequency MFs on morphometric parameters and the activity of physiological processes in wheat (Triticum aestivum L.). It is shown that the MF effect is more pronounced for transient processes - photosynthesis reactions and changes in electrical potential caused by turning on light. For light-induced electrical reactions, the dependence of the severity of the effect on the frequency of the applied MF was demonstrated. It is shown that the most pronounced effect occurs in the 14.3 Hz field, which corresponds to the second harmonic of the Schumann resonance. The predominant sensitivity of signal-regulatory systems gives reason to assume the influence of MFs with Schumann resonance frequencies on the interaction of plants with environmental factors under conditions of a changed electromagnetic environment. Such conditions can occur, for example, with an increase in lightning activity caused by climate change, which serves as the basis for the generation of Schumann resonances, and with the development of artificial ecosystems outside the Earth's atmosphere.

24 h cold exposure (4°C) is sufficient to reduce pathogen susceptibility in Arabidopsis thaliana against the virulent Pseudomonas syringae pv. tomato (Pst) strain even when the infection occurs five days later. This priming effect is independent of the immune regulator Enhanced Disease Susceptibility 1 (EDS1) and can be observed in the immune-compromised eds1-2 null mutant. In contrast, cold priming-reduced Pst susceptibility is strongly impaired in knock-out lines of the stromal and thylakoid ascorbate peroxidases (sAPX/tAPX) highlighting their relevance for abiotic stress-related increased immune resilience. Here, we extended our analysis by generating an eds1 sapx double mutant. eds1 sapx showed eds1-like resistance and susceptibility phenotypes against Pst strains containing the effectors avrRPM1 and avrRPS4. In comparison to eds1-2, susceptibility against the wildtype Pst strain was constitutively enhanced in eds1 sapx. Although a prior cold priming exposure resulted in reduced Pst titers in eds1-2, it did not alter Pst resistance in eds1 sapx. This demonstrates that the genetic sAPX requirement for cold priming of basal plant immunity applies also to an eds1 null mutant background.

Rainfall, wind and touch, as mechanical forces, were mimicked on 6-week-old soil-grown tomato and potato under controlled conditions. Expression level changes of xyloglucan endotransglucosylase/hydrolase genes (XTHs) of tomato (Solanum lycopersicum L. cv. Micro Tom; SlXTHs) and potato (Solanum tuberosum L. cv. Desirée; StXTHs) were analyzed in response to these mechanical forces. Transcription intensity of every SlXTHs of tomato was altered in response to rainfall, while the expression intensity of 72% and 64% of SlXTHs was modified by wind and touch, respectively. Ninety-one percent of StXTHs (32 out of 35) in potato responded to the rainfall, while 49% and 66% of the StXTHs were responsive to the wind and touch treatments, respectively. As previously demonstrated, all StXTHs were responsive to ultrasound treatment, and all were sensitive to one or more of the environmental mechanical factors examined in the current study. To our best knowledge, this is the first study to demonstrate that these ubiquitous mechanical environmental cues, such as rainfall, wind and touch, influence the transcription of most XTHs examined in both species.

Foeniculum vulgare Mill. commonly known as fennel, is a globally recognized aromatic medicinal plant and culinary herb with widespread popularity due to its antimicrobial, antioxidant, carminative, and diuretic properties, among others. Although the phenotypic effects of salinity stress have been previously explored in fennel, the molecular mechanisms underlying responses to elevated salinity in this plant remain elusive. MicroRNAs (miRNAs) are tiny, endogenous, and extensively conserved non-coding RNAs (ncRNAs) typically ranging from 20 to 24 nucleotides (nt) in length that play a major role in a myriad of biological functions. In fact, a number of miRNAs have been extensively associated with responses to abiotic stress in plants. Consequently, employing computational methodologies and rigorous filtering criteria, 40 putative miRNAs belonging to 25 different families were characterized from fennel in this study. Subsequently, employing the psRNATarget tool, a total of 67 different candidate target transcripts for the characterized fennel miRNAs were predicted. Additionally, the expression patterns of six selected fennel miRNAs (i.e. fvu-miR156a, fvu-miR162a-3p, fvu-miR166a-3p, fvu-miR167a-5p, fvu-miR171a-3p, and fvu-miR408-3p) were analyzed under salinity stress conditions via qPCR. This article holds notable significance as it identifies not only 40 putative miRNAs in fennel, a non-model plant, but also pioneers the analysis of their expression under salinity stress conditions.

The capability of the transition from skotomorphogenesis-to-photomorphogenesis (de-etiolation) is requisite for seedling survival and development. However, how carbohydrate in germinating seeds controls seedling de-etiolation remains unclear. Mu et al. (2022) investigated the regulatory roles of soluble sugars (such as, glucose or sucrose) on de-etiolation during the transition from skotomorphogenesis-to-photomorphogenesis. The authors revealed that in the dark, sucrose/glucose in germinating seeds induces ethylene production/signaling. Ethylene signaling promotes the stability of EIN3 (ETHYLENE-INSENSITIVE3), a key component in the ethylene signaling pathway. In turn, EIN3 directly binds to the promoter of SUC2 (Sucrose Transporter 2), encoding a major sucrose transporter, to repress SUC2 transcription. The resulting phloem loading of sucrose is blocked, and thereby the accumulation of sucrose is elevated in etiolated seedling cotyledons. When exposed to light irradiation, accumulated sucrose/glucose inducing ethylene elevates the stability of EIN3, repressing phyA (encoding the photoreceptor of a far-red light/the inhibitor of a cotyledon greening) expression to promote de-etiolation. In this study, we mainly discuss the findings (low sugars promote de-etiolation) of Mu et al. (2021) and further find that excess sugars inhibit de-etiolation.

Currently, applying lime to cadmium (Cd)-contaminated paddy fields to increase pH and reduce Cd availability is an effective method to control excessive Cd levels in rice grain. However, under hydroponic conditions, the impact of increased pH on Cd accumulation in different rice varieties remains unclear. This study employed three rice varieties (Yuzhenxiang, Shaoxiang 100, Xiangwanxian 12) with different Cd accumulation characteristics under different pH and long-term treatment with 1 μM CdCl₂, to study the effect of pH on growth and Cd accumulation in different rice varieties. The result showed that as pH shifted from 5 to 8, the SPAD values, shoot dry weight, and plant height of the three rice varieties significantly decreased. The main root length, root volume, and root dry weight of Yuzhenxiang, and Shaoxiang100 significantly decreased. Conversely, the root architecture indicators of Xiangwanxian 12 did not change significantly. As for element accumulation, increasing the pH significantly increased the content of Mn in both the shoots and roots of all three varieties. Yuzhenxiang significantly reduced Cd content in both the shoots and roots of rice, while Shaoxiang100 significantly increased Cd content in both parts. Xiangwanxian 12 showed a significant increase in Cd content in the shoots but a decrease in the roots. In terms of subcellular distribution, Yuzhenxiang significantly reduced Cd concentrations in the cell wall and organelles of root cells, resulting in lower Cd concentrations in the root tissue. Conversely, Shaoxiang100 significantly increased Cd concentrations in the cell wall, organelles, and soluble fractions of root cells, leading to higher Cd concentrations in the root tissue. Xiangwanxian 12 also exhibited a decrease in Cd concentrations in the cell wall, organelles, and soluble fraction of root cells, resulting in lower Cd concentrations in the root tissue. Additionally, the expression of the OsNRAMP5 and OsHMA3 gene was significantly increased in Shaoxiang 100, while no significantly change in Yuzhenxiang and Xiangwanxian 12. These results provide important guidance on the impact of pH on Cd accumulation during the vegetative growth stage of different rice varieties.

Crabapple is a valuable tree species in gardens due to its captivating array of flower and leaf colors, rendering it a favored choice in landscaping. The economic and ornamental values of Malus crabapple are closely associated with the biosynthesis of anthocyanin, a pigment responsible for its vibrant hues. The intricate regulation of anthocyanin biosynthesis involves the concerted activity of various genes. However, the specific mechanism governing this process in crabapple warrants in-depth exploration. In this study, we explored the inhibitory role of MsMYB62-like in anthocyanin biosynthesis. We identified MsDFR and MsANS as two downstream target genes of MsMYB62-like. These genes encode enzymes integral to the anthocyanin biosynthetic pathway. The findings demonstrate that MsMYB62-like directly binds to the promoters of MsDFR and MsANS, resulting in the downregulation of their expression levels. Additionally, our observations indicate that the plant hormone cytokinins exert a suppressive effect on the expression levels of MsMYB62-like, while concurrently upregulating MsDFR and MsANS. This study reveals that the MsMYB62-like-MsDFR/MsANS module plays an important role in governing anthocyanin levels in Malus crabapple. Notably, the regulatory interplay is modulated by the plant hormone cytokinins.

Adjusting the timing of floral transition is essential for reproductive success in plants. A number of flowering regulators integrate internal and external signals to precisely determine the time to flower. We here report that the AGAMOUS-LIKE 6 (AGL6) - EARLY FLOWERING 3 (ELF3) module regulates flowering in the FLOWERING LOCUS T (FT)-dependent pathway in Arabidopsis. The AGL6 transcriptional repressor promotes floral transition by directly suppressing ELF3, which in turn directly represses FT expression that acts as a floral integrator. Indeed, ELF3 is epistatic to AGL6 in the control of floral transition. Overall, our findings propose that the AGL6-ELF3 module contributes to fine-tuning flowering time in plants.

The rising prevalence of viral-induced diseases, particularly those caused by certain strains, poses a substantial risk to the genetic diversity of Solanaceae crops and the overall safety of horticultural produce. According to the "gene-for-gene" hypothesis, resistance proteins are capable of selectively identifying nontoxic effectors produced by pathogens, as they are under purview of the host's immune defenses. The sensitivity and responsiveness of Solanaceae plants to viral attacks play a crucial role in shaping the outcomes of their interactions with viruses. Pathogenic organisms, devise an array of infection tactics aimed at circumventing or neutralizing the host's immune defenses to facilitate effective invasion. The invasion often accomplishes by suppressing or disrupting the host's defensive mechanisms or immune signals, which are integral to the infection strategies of such invading pathogens. This comprehensive review delves into the myriad approaches that pathogenic viruses employ to infiltrate and overcome the sophisticated immune system of tomatoes. Furthermore, the review explores the possibility of utilizing these viral strategies to bolster the resilience of horticultural crops, presenting a hopeful direction for forthcoming progress in plant health and agricultural stability.

The flooding of agricultural land leads to hypoxia and nitrate leaching. While understanding the plant's response to these conditions is essential for crop improvement, the effect of extended nitrate limitation on subsequent hypoxia has not been studied in an organ-specific manner. We cultivated Arabidopsis thaliana without nitrate for 1 week before inducing hypoxia by bubbling the hydroponic solution with nitrogen gas for 16 h. In the roots, the transcripts of two transcription factor genes (HRA1, HRE2) and three genes involved in fermentation (SUS4, PDC1, ADH1) were ~10- to 100-fold upregulated by simultaneous hypoxia and nitrate starvation compared to the control condition (replete nitrate and oxygen). In contrast, this hypoxic upregulation was ~5 to 10 times stronger when nitrate was available. The phytoglobin genes PGB1 and PGB2, involved in nitric oxide (NO) scavenging, were massively downregulated by nitrate starvation (~1000-fold and 10⁵-fold, respectively), but only under ambient oxygen levels; this was reflected in a 2.5-fold increase in NO concentration. In the leaves, HRA1, SUS4, and RAP2.3 were upregulated ~20-fold by hypoxia under nitrate starvation, whereas this upregulation was virtually absent in the presence of nitrate. Our results highlight that the plant's responses to nitrate starvation and hypoxia can influence each other.