Genome-Wide Identification and Characterization of the bHLH Gene Family and Its Response to Abiotic Stresses in Carthamus tinctorius.

The basic helix-loop-helix (bHLH) transcription factors possess DNA-binding and dimerization domains and are involved in various biological and physiological processes, such as growth and development, the regulation of secondary metabolites, and stress response. However, the bHLH gene family in C. tinctorius has not been investigated. In this study, we performed a genome-wide identification and analysis of bHLH transcription factors in C. tinctorius. A total of 120 CtbHLH genes were identified, distributed across all 12 chromosomes, and classified into 24 subfamilies based on their phylogenetic relationships. Moreover, the 120 CtbHLH genes were subjected to comprehensive analyses, including protein sequence alignment, evolutionary assessment, motif prediction, and the analysis of promoter cis-acting elements. The promoter region analysis revealed that CtbHLH genes encompass cis-acting elements and were associated with various aspects of plant growth and development, responses to phytohormones, as well as responses to both abiotic and biotic stresses. Expression profiles, sourced from transcriptome databases, indicated distinct expression patterns among these CtbHLH genes, which appeared to be either tissue-specific or specific to certain cultivars. To further explore their functionality, we determined the expression levels of fifteen CtbHLH genes known to harbor motifs related to abiotic and hormone responses. This investigation encompassed treatments with ABA, salt, drought, and MeJA. The results demonstrated substantial variations in the expression patterns of CtbHLH genes in response to these abiotic and hormonal treatments. In summary, our study establishes a solid foundation for future inquiries into the roles and regulatory mechanisms of the CtbHLH gene family.

[Occurrence regularity and integrated control of leaf miner in safflower].

Leaf miner is one of the major pests on safflower, which causes yield loss and poor quality seriously. "Weihonghua", "nine safflower varieties" and "three chemical insecticides" as materials that used to evaluate variety and regularity of leaf miner, safflower resistant level, and different proportions insecticides in field efficiency test. The results showed that Liriomyza sativae and L. huidobrensis accounted for 80%, the peak period of two pests was all in July; but Phytomyza horticola is relative less, its peak period occured in June. Three were great difference of resistance to leaf miner among safflower varieties, FQ12 and YJ65 expressed higher resistibility to leaf miner by ratio method. With abamectin 2% emulsifiable concentrate diluted for 2 000 times, or the mixture three insecticides(bifenthrin 20% water emulsions, thiamethoxam 25% water dispersible granule, abamectin 2% emulsifiable concentrate=1∶1∶1) diluted for 3 000 times, which were sprayed on leaves at squaring stage and lethal rate was 96% after 48 h in the study. Through comparative study on the variety and regularity of leaf miner, screen for resistant varieties to leaf miner and for high efficiency pesticide. The study provides theoretical basis and reference for integrated pest management of leaf miner.

[Research on regional distribution and industrial status analysis of genuine medicinal resources of flowers in Henan province].

Flower medicinal materials usually refer to Chinese medicinal materials with a complete flower,inflorescence,or part of a flower as the different medicinal parts,they have an important share in the Chinese herbal medicine market and appeared frequently in Chinese medicine prescriptions. Firstly,the species and regional distribution of the flower medicinal materials resources in China were briefly summarized. Secondly,the characteristics,yield,producing area and origin distribution of the main flower medicinal materials in Henan province were discussed. Finally,the present situation and the main problems of the flower medicinal materials industry in Henan province were comprehensively analyzed,and the corresponding industrial development countermeasures were put forward.This research was intended to provide decision-making demonstration and scientific basis for the rational exploitation and utilization of resources,breeding of new varieties,planting division,production layout and the healthy and sustainable development of the flower medicinal materials industry in Henan province.

Plant-mediated gene silencing of an essential olfactory-related Gqα gene enhances resistance to grain aphid in common wheat in greenhouse and field.

BACKGROUND: Grain aphid (Sitobion avenae F.) is a dominant pest that limits cereal crop production around the globe. Gq proteins have important roles in signal transduction in insect olfaction. Plant-mediated RNA interference (RNAi) has been widely studied in insect control, but its application for the control wheat aphid in the field requires further study. Here, we used double-stranded (ds)RNA feeding to verify the potential of selected Gqα fragments for host-mediated RNAi, and then evaluated the effect of RNAi on aphid olfaction in transgenic wheat in the greenhouse and field. RESULTS: Gqα gene was expressed in the aphid life cycle, and a 540 bp fragment shared 98.1% similarity with the reported sequence. dsGqα feeding reduced the expression of Gqα, and both reproduction and molting in the grain aphid. Feeding transgenic lines in the greenhouse downregulated expression of aphid Gqα, and significantly reduced reproduction and molting numbers. Furthermore, our field results indicate that transgenic lines have lower aphid numbers and higher 1000-grain weight than an unsprayed wild-type control. CONCLUSION: Plant-mediated silencing of an essential olfactory-related Gqα gene could enhance resistance to grain aphid in common wheat in both the greenhouse and the field. © 2018 Society of Chemical Industry.

Plant-mediated RNAi of grain aphid CHS1 gene confers common wheat resistance against aphids.

BACKGROUND: Chitin is an important component of the insect exoskeleton and peritrophic membrane. Chitin synthase 1 (CHS1) is a key enzyme in the chitin synthesis pathway, and has a role in insect molting and growth. Plant-mediated RNA interference (RNAi) has been used as a more target-specific and environmentally safe approach to prevent and control agricultural insects. The aims of this study were to use grain aphid (Sitobion avanae) CHS1 as the target gene and to produce transgenic wheat lines for aphid control via plant-mediated RNAi. RESULTS: Expression levels of CHS1 changed at different developmental stages. After feeding on the representative T3 transgenic lines Tb5-2 and Tb10-3, CHS1 expression levels in grain aphid decreased by 50.29% and 45.32%, respectively; and total and molting aphid numbers reduced significantly, compared with controls. Consistent with this, aphid numbers in mixed natural populations reduced significantly in the respective T4 and T5 transgenic lines under field conditions, and T5 transgenic lines had higher grain weight compared with the unsprayed insecticide wild-type and insecticide-sprayed wild-type. CONCLUSION: These results indicate that plant-mediated RNAi of the grain aphid CHS1 gene confers common wheat resistance against aphids. © 2018 Society of Chemical Industry.

Silencing of a lipase maturation factor 2-like gene by wheat-mediated RNAi reduces the survivability and reproductive capacity of the grain aphid, Sitobion avenae.

Lipase maturation factor (LMF) family proteins are required for the maturation and transport of active lipoprotein lipases. However, the specific roles of LMF2 remain unknown. In this study, a grain aphid lmf2-like gene fragment was cloned and was highly similar in sequence to a homologous gene in the pea aphid, Acyrthosiphon pisum. An RNAi vector was constructed with this fragment and used for wheat transformation. The expression of the lmf2-like gene in aphid, as well as the growth and reproduction of the aphids, was analyzed after feeding on the transgenic wheat. There were no significant differences in the expression of the lmf2-like gene over development. The expression of the lmf2-like gene was significantly reduced by 27.6% on the fifth day, and 57.6% on the 10th day after feeding. The total number of aphids produced on the transgenic plants was less than the number produced on control plants, and the difference became significant or after 2 weeks. The molting numbers were also reduced in the aphids reared on the transgenic plants. Our findings indicate that lmf2-like genes may have potential as a target gene for the control of grain aphids and show that feeding aphids with wheat expressing lmf2-like RNAi resulted in significant reductions in survival and reproduction.

Inheritance and QTL mapping of related root traits in soybean at the seedling stage.

KEY MESSAGE: This study provides a foundation for further research on root genetic regulation and molecular breeding with emphasis on correlations among root traits to ensure robust root growth and well-developed root systems. A set of 447 recombinant inbred lines (RILs) derived from a cross between Jingdou23 (cultivar, female parent) and ZDD2315 (semi-wild, male parent) were used to analyze inheritance and detect QTLs related to root traits at the seedling stage using major gene plus polygene mixed inheritance analysis and composite interval mapping. The results showed that maximum root length (MRL) was controlled by three equivalent major genes, lateral root number (LRN) was controlled by two overlapping major genes, root weight (RW) and volume (RV) were controlled by four equivalent major genes. Hypocotyl length (HL) was controlled by four additive main genes, and hypocotyl weight (HW) was controlled by four additive and additive × additive epistatic, major genes; however, polygene effects were not detected in these traits. Shoot weight (SW) was controlled by multi-gene effects, but major gene effects were not detected. Twenty-four QTLs for MRL, LRN, RW, RV, SW, HL, HW were mapped on LG A1 (chromosome 5), LG A2 (chromosome 8), LG B1 (chromosome 11), LG B2 (chromosome 14), LG C2 (chromosome 6), LG D1b (chromosome 2), LG F_1 (chromosome 13), LG G (chromosome 18), LG H_1 (chromosome 12), LG H_2 (chromosome 12), LG I (chromosome 20), LG K_2 (chromosome 9), LG L (chromosome 19), LG M (chromosome 7), LG N (chromosome 3), LG O (chromosome 10), separately. Root traits were shown to have complex genetic mechanisms at the seedling stage, SW was controlled by multi-gene effects, and the other six traits were controlled by major gene effects. It is concluded that correlations among root traits must be considered to improve the development of beneficial root traits.

Silencing of an aphid carboxylesterase gene by use of plant-mediated RNAi impairs Sitobion avenae tolerance of Phoxim insecticides.

RNA interference (RNAi) describes the ability of double-stranded RNA (dsRNA) to inhibit homologous gene expression at the RNA level. Its specificity is sequence-based and depends on the sequence of one strand of the dsRNA corresponding to part or all of a specific gene transcript. In this study we adopted plant-mediated RNAi technology that targets Sitobion avenae (S. avenae) to enable gene silencing in the aphid and to minimize handling of the insects during experiments. S. avenae was selected for this study because it causes serious economic losses to wheat throughout the world. The carboxylesterase (CbE E4) gene in S. avenae was homologously cloned, which increased synthesis of a protein known to be critical to the resistance (tolerance) this species has developed to a wide range of pesticides. A plant RNAi vector was constructed, and transgenic Triticum aestivum (dsCbE1-5 and dsCbE2-2 lines) expressing CbE E4 dsRNA were developed. S. avenae were fed on dsCbE1-5 and dsCbE2-2 lines stably producing the CbE E4 dsRNA. CbE E4 gene expression in S. avenae was reduced by up to 30-60%. The number of aphids raised on dsCbE1-5 and dsCbE2-2 was lower than the number raised on non-transgenic plants. A solution of CbE E4 enzyme from S. avenae fed on dsCbE1-5 and dsCbE2-2 plants hydrolyzed only up to 20-30% Phoxim solution within 40 min whereas a solution of the enzyme from CbE E4 fed on control plants hydrolyzed 60% of Phoxim solution within 40 min. CbE E4 gene silencing was achieved by our wheat-mediated RNAi approach. This plant-mediated RNAi approach for addressing degradation-based pesticide resistance mechanisms in aphids and may prove useful in pest management for diverse agro-ecosystems.