[Research status of insect infestation of Chinese medicinal materials during storage].

During the storage process, Chinese medicinal materials are susceptible to insect infestation due to their own nature and external storage factors. Infestation by insects can have varying impacts on the materials. In mild cases, it affects the appearance and reduces consumer purchasing power, while in severe cases, it affects the quality, reduces medicinal value, and introduces impurities such as insect bodies, excrement, and secretions, resulting in significant contamination of the medicinal materials. This study reviewed the rele-vant factors influencing insect infestation in Chinese medicinal materials and the compositional changes that occur after infestation and summarized maintenance measures for preventing insect infestation. Additionally, it provided an overview of detection techniques applicable to identifying insect infestation during the storage of Chinese medicinal materials. During the storage process, insect infestation is the result of the combined effects of biological factors(source, species, and population density of insects), intrinsic factors(moisture, chemical composition, and metabolism), and environmental factors(temperature, relative humidity, and oxygen content). After infestation, there are significant changes in the content of constituents in the medicinal materials. By implementing strict pre-storage inspections, regular maintenance after storage, and appropriate storage and maintenance methods, the occurrence of insect infestation can be reduced, and the preservation rate of Chinese medicinal materials can be improved. The storage and maintenance of Chinese medicinal materials are critical for ensuring their quality. Through scientifically standardized storage and strict adherence to operational management standards, the risk of insect infestation can be minimized, thus guaranteeing the quality of Chinese medicinal materials.

StHAB1, a negative regulatory factor in abscisic acid signaling, plays crucial roles in potato drought tolerance and shoot branching.

Abscisic acid (ABA) is critical in drought tolerance and plant growth. Group A protein type 2C phosphatases (PP2Cs) are negative regulators of ABA signaling and plant adaptation to stress. Knowledge about the functions of potato group A PP2Cs is limited. Here, we report that the potato group A PP2C StHAB1 is broadly expressed in potato plants and strongly induced by ABA and drought. Suppression of StHAB1 enhanced potato ABA sensitivity and drought tolerance, whereas overexpression of the dominant mutant StHAB1G276D compromised ABA sensitivity and drought tolerance. StHAB1 interacts with almost all ABA receptors and the Snf1-Related Kinase OST1. Suppressing StHAB1 and overexpressing StHAB1G276D alter potato growth morphology; notably, overexpression of StHAB1G276D causes excessive shoot branching. RNA-sequencing analyses identified that the auxin efflux carrier genes StPIN3, StPIN5, and StPIN8 were up-regulated in StHAB1G276D-overexpressing axillary buds. Correspondingly, the auxin concentration was reduced in StHAB1G276D-overexpressing axillary buds, consistent with the role of auxin in repressing lateral branch outgrowth. The expression of BRANCHED1s (StBRC1a and StBRC1b) was unchanged in StHAB1G276D-overexpressing axillary buds, suggesting that StHAB1G276D overexpression does not cause axillary bud outgrowth via regulation of BRC1 expression. Our findings demonstrate that StHAB1 is vital in potato drought tolerance and shoot branching.

Suppression of the tonoplast sugar transporter, StTST3.1, affects transitory starch turnover and plant growth in potato.

Transitory starch and vacuolar sugars function as highly dynamic pools of instantly accessible metabolites in plant leaf cells. Their metabolic regulation is critical for plant survival. The tonoplast sugar transporters (TSTs), responsible for sugar uptake into vacuoles, regulate cellular sugar partitioning and vacuolar sugar accumulation. However, whether TSTs are involved in leaf transient starch turnover and plant growth is unclear. Here, we found that suppressing StTST3.1 resulted in growth retardation and pale green leaves in potato plants. StTST3.1-silenced plants displayed abnormal chloroplasts and impaired photosynthetic performance. The subcellular localization assay and the oscillation expression patterns revealed that StTST3.1 encoded a tonoplast-localized protein and responded to photoperiod. Moreover, RNA-seq analyses identified that starch synthase (SS2 and SS6) and glucan water, dikinase (GWD), were downregulated in StTST3.1-silenced lines. Correspondingly, the capacity for starch synthesis and degradation was decreased in StTST3.1-silenced lines. Surprisingly, StTST3.1-silenced leaves accumulated exceptionally high levels of maltose but low levels of sucrose and hexose. Additionally, chlorophyll content was reduced in StTST3.1-silenced leaves. Analysis of chlorophyll metabolic pathways found that Non-Yellow Coloring 1 (NYC1)-like (NOL), encoding a chloroplast-localized key enzyme that catalyzes the initial step of chlorophyll b degradation, was upregulated in StTST3.1-silenced leaves. Transient overexpression of StNOL accelerated chlorophyll b degradation in tobacco leaves. Our results indicated that StTST3.1 is involved in transitory starch turnover and chlorophyll metabolism, thereby playing a critical role in normal potato plant growth.

Lead exposure dose-dependently affects oxidative stress, AsA-GSH, photosynthesis, and mineral content in pakchoi (Brassica chinensis L.).

Lead (Pb) is a heavy metal pollutant and negatively affects agriculture and ecosystems. Pb can cause oxidative stress and abnormal plant growth. The ascorbic acid-glutathione (AsA-GSH) cycle mainly exists in chloroplasts and resists oxidative stress, scavenges reactive oxygen radicals, and maintains normal photosynthesis. However, the dosage related effects of Pb on pakchoi photosynthesis, via oxidative stress and the AsA-GSH system, remains unclear. In this study, various Pb dosage stress models were tested (low: 300 mg/kg; medium: 600 mg/kg; high: 900 mg/kg). Pb stress induced a dose-dependent increase in Pb content in pakchoi leaves (P < 0.05). Principal component analysis showed that Se, B, and Pb were significantly and negatively correlated. Pb stress also increased MDA content and decreased antioxidant enzymes SOD, GSH-Px, and T-AOC activities (P < 0.05). We also found that Vc content, as well as the GSH/GSSG ratio, decreased. Additionally, Pb stress destroyed chloroplast structure, decreased photosynthesis indicators Pn, Tr, Gs, Ci and VPD, and attenuated Fv/Fm and Fv/Fo (P < 0.05). In the high-dose group, the contents of chlorophyll a, chlorophyll b, and carotenoids decreased significantly, while the expression of chloroplast development genes (GLK, GLN2) decreased (P < 0.05). Our data suggest that Pb stress leads to dosage-dependent, aberrant photosynthesis by inhibiting the AsA-GSH system in pakchoi. This study expands the Pb toxicology research field and provides indications for screening antagonists.

Suppression of the tonoplast sugar transporter StTST3.2 improves quality of potato chips.

Which sugar transporter regulates sugar accumulation in tubers is largely unknown. Accumulation of reducing sugar (RS) in potato (Solanum tuberosum L.) tubers negatively affects the quality of tubers undergoing the frying process. However, little is known about the genes involved in regulating RS content in tubers at harvest. Here, we have identified two tonoplast sugar transporter (TST) 3-type isoforms (StTST3.1 and StTST3.2) in potato. Quantitative real-time PCR results indicate that StTST3.1 and StTST3.2 possess distinct expression patterns in various potato tissues. StTST3.2 was found to be the expressed TST3-type isoform in tubers. Further subcellular localization analysis revealed that StTST3.2 was targeted to the tonoplast. Silencing of StTST3.2 in potato by stable transformation resulted in significantly lower RS content in tubers at harvest or after room temperature storage, suggesting StTST3.2 plays an important role in RS accumulation in tubers. Accordingly, compared with the unsilenced control, potato chips processed from StTST3.2-silenced tubers exhibited lighter color and dramatically decreased acrylamide production at harvest or after room temperature storage. In addition, we demonstrated that silencing of StTST3.2 has no significant effect on potato growth and development. Thus, suppression of StTST3.2 could be another effective approach for improving processing quality and decreasing acrylamide content in potato tubers.

Starvation on First or Second Day of Adulthood Reverses Larval-Stage Decision to Migrate in Beet Webworm (Lepidoptera: Pyralidae).

A facultative commitment to adult migration in the larval stage can be modified again after adult emergence in some Lepidoptera when influenced by an appropriate environmental cue during a sensitive stage. This phenomenon is termed secondary regulation of migration. The sensitive stage in adult beet webworm, Loxostege sticticalis L. (Lepidoptera: Pyralidae), was determined experimentally by starvation of presumed migrant females reared from gregarious-phase larvae (induced by crowding at 10 larvae per 650-ml jar). When presumed migrant adults were starved for 24 h on either of the first 2 d after emergence, the preoviposition period was shortened. In contrast, preoviposition periods were not significantly shortened for migrants starved on day 3 or when starvation lasted for more than 1 d after emergence. Because the preoviposition period corresponds to the migratory period in beet webworm, the results suggest that the first 2 d of adult life in the beet webworm is the sensitive stage during which presumed migrants can be switched to residents by an appropriate environmental cue. During the sensitive stage or not, starvation did not influence lifetime fecundity, oviposition period, longevity, or hatching rate of eggs laid by the starvation-stressed moths. Starvation on the first day also increased tethered flight performance and accelerated both flight muscle and ovarian development. The results suggest that a pulse of starvation in the sensitive period may inhibit the expected migration by accelerating and compressing the cycle of migratory flight muscle development and degeneration, while accelerating ovarian development, which is normally suppressed until after migration.