Search

Plant genetic transformation is a crucial step for applying biotechnology such as genome editing to basic and applied plant science research. Its success primarily relies on the efficiency of gene delivery into plant cells and the ability to regenerate transgenic plants. In this study, we have examined the effect of several developmental regulators (DRs), including PLETHORA (PLT5), WOUND INDUCED DEDIFFERENTIATION 1 (WIND1), ENHANCED SHOOT REGENERATION (ESR1), WUSHEL (WUS) and a fusion of WUS and BABY-BOOM (WUS-P2A-BBM), on in planta transformation through injection of Agrobacterium tumefaciens in snapdragons (Antirrhinum majus). The results showed that PLT5, WIND1 and WUS promoted in planta transformation of snapdragons. An additional test of these three DRs on tomato (Solanum lycopersicum) further demonstrated that the highest in planta transformation efficiency was observed from PLT5. PLT5 promoted calli formation and regeneration of transformed shoots at the wound positions of aerial stems, and the transgene was stably inherited to the next generation in snapdragons. Additionally, PLT5 significantly improved the shoot regeneration and transformation in two Brassica cabbage varieties (Brassica rapa) and promoted the formation of transgenic calli and somatic embryos in sweet pepper (Capsicum annum) through in vitro tissue culture. Despite some morphological alternations, viable seeds were produced from the transgenic Bok choy and snapdragons. Our results have demonstrated that manipulation of PLT5 could be an effective approach for improving in planta and in vitro transformation efficiency, and such a transformation system could be used to facilitate the application of genome editing or other plant biotechnology application in modern agriculture.

This letter proposes novel methods for designing two-dimensional (2-D) weight-constrained codes for reducing the parasitic currents in the crossbar resistive memory array. In particular, we present efficient encoding/decoding algorithms for capacity-approaching 2-D weight-constrained codes of size $m \times n$ , where each row has a weight $pn$ with $p ; and each column has a weight $qm$ with $q \leq 1/2$ . We show that the designed codes provide higher code rates compared to the prior art codes for $p \le 1/2$ and $q \le 1/2$ .

The clustered, regularly interspaced, short palindromic repeat associated endonuclease 9 (CRISPR/Cas9) system has emerged as a powerful approach for precision breeding to create plants with desirable traits. However, the CRISPR/Cas9 system relies heavily on an efficient plant transformation system that is usually time-consuming and costly. Here, we have constructed a CRISPR-Cas9 vector with neomycin phosphotransferase II and green fluorescent protein (eGFP-NPTII), where the high expression of GFP during plant regeneration allowed us to minimize the positional effect on T-DNA expression and facilitate screening T-DNA-free mutants. Successful gene editing using CRISPR/Cas9 has been illustrated in different plant species, but an important aesthetic characteristic of leaf variegation remained unexplored. With the newly designed construct, we have targeted the variegation gene LsVAR2 in lettuce. Our results indicated that LsVAR2 is closely related to both AtFtsH2 and AtFtsH8, in which homozygous mutations lead to an albino phenotype while a variegated phenotype was induced by CRISPR/Cas9 de novo gene editing. In conclusion, the unique design of our CRISPR/Cas9 construct could efficiently edit the target gene and ease the screening of non-TDNA mutants through detecting GFP signals during plant regeneration and progeny segregation. Additionally, the success of gene-editing of LsVAR2 in lettuce demonstrates proof in this method to develop novel plant breeding materials for valuable horticultural plant species.

Hand pollination is a necessary assisting method for pitaya (Selenicereus spp.) production to achieve a high yield. With the cultivated area increasing at an exponential rate in recent years, a comprehensive study of the pollination process was conducted. We developed an ideal medium for pitaya pollen in vitro germination in this study, then tested the activity of pollen collected from or stored for various time periods. We discovered that those collected between 2 h before blooming and 6 h after blooming had the higher germination rates (27.2–65.1%), the highest activity was at 2 h after blooming, and that storing them at 4°C for 24 hours reduces their germination rate from 65.2 percent to 35.5 percent and their production to about 82%. As a result, pollinating plants with pollen that has been held for more than 24 hours is not recommended unless a breakthrough in pollen storage is achieved. We also discovered that stigma receptivity and pollen activity are synchronized, which together determines the rate of fruit setting and the size of the fruit. Pollination within 6 hours after flowering offers the optimum fruit setting percentage and size, while pollination at 6:00 pm, 2 hours before blooming, is also a good alternative; however, pollination at 6:00 am the next morning is expected to result in a 23 % drop in productivity. These findings will be beneficial for reproductive biology research, as well as laying the groundwork for hand pollination to boost pitaya output and breeding efficiency.

Snapdragon (Antirrhinum majus L.) is a popular ornamental and model plant species, and the recently released reference genome could greatly boost its utilization in fundamental research. However, the lack of an efficient genetic transformation system is still a major limiting factor for its full application in genetic and molecular studies. In this study, a simple method for quick regeneration and efficient Agrobacterium-mediated transformation of snapdragon was developed. Cotyledon petiole and hypocotyl explants derived from two-week-old seedlings were cultured on MS media supplemented with 2 mg/L zeatin (ZT), 0.2 mg/L 1-naphthaleneacetic acid (NAA), and 2 mg/L AgNO3, and adventitious shoots were regenerated through organogenesis with an average regeneration of 48.00% and 41.33%, respectively. By contrast, the regeneration frequency was only 22.67% for cotyledon petiole and 25.67% for hypocotyl explants in the absence of AgNO3. Moreover, the application of AgNO3 promoted indirect shoot organogenesis, while direct shoot organogenesis occurred in the absence of AgNO3 from both hypocotyl or cotyledon petiole explants. Agrobacterium-mediated genetic transformation systems were developed with this high-efficient regeneration system. The transformation efficiency has been improved from 0 to 1% through the direct shoot organogenesis to 3 to 4% via the indirect shoot organogenesis. This efficient regeneration and genetic transformation method could be important for future use of snapdragon as a model plant to address some fundamental questions which are hard to be solved by using other model plant species, and to accelerate the breeding process through CRISPR/Cas9 genome editing. Genetic transformation of snapdragon was significantly improved by applying AgNO3 to induce indirect organogenesis, which will substantially facilitate its fundamental research as well as molecular breeding.

Snapdragon (Antirrhinum majus) is one of top ten fresh-cut flowers in the United States; however, its short vase life limits its marketability. The purposes of this study were to test the effects of LED light, exogenous melatonin and one ethylene production inhibitor, AVG, on the quality of pre-harvest snapdragon and the prolongation of vase life after post-harvesting. Our results showed that snapdragon treated with 10 h white light followed by 6 h blue light (WB) inhibited stem elongation and lengths of the inflorescences, reduced the number of florets and vase life. On the contrary, snapdragon treated with 10 h white light, 3 h red light, 3 h blue light (WRB) significantly promoted stem elongation, lengths of the inflorescences, and increased the size and number of florets. The lengths of stems and inflorescences increased significantly in all melatonin treatments while quantity and size of florets only increased with 200 µmol·L-1 melatonin application. Noticeably, vase life was significantly extended with 200 µmol·L-1 melatonin application and shortened with WB treatment. In contrast to melatonin, all AVG treatments resulted in decreases of the floret size; and changes in stem elongation and inflorescence length were only observed in the treatment with 100 µmol·L-1AVG. These results showed that pre-harvest treatment with WBR and melatonin can effectively improve the post-harvest quality of snapdragon flowers and 200 µmol·L-1 of melatonin extended their vase life.

In this article, an efficient concatenation of error correction codes with constrained codes is proposed. Generally, constrained codes are designed to match specified channels, whereas error correction coding schemes are designed to correct the channel errors. Both play important roles to ensure the integrity of data in data storage systems. In this study, we first investigate the design of k-constrained codes combined with a low-density parity-check (LDPC) code, and then we extend the idea to the design of dc-free k-constrained LDPC codes. Simulation results show that the proposed designs achieve an improved bit error rate (BER) performance, compared to prior art schemes. In particular, the proposed design for the dc-free k-constrained codes not only fully eliminates the effect of error propagation in a reverse configuration but also achieves significant dc suppression.

Shingled magnetic recording (SMR) is regarded as the most influential technology for the next-generation magnetic recording systems. The SMR tracks are partly overlapped by each other, and the SMR systems can obtain higher area densities by increasing track per inch density. As a result, this brings more interference from the adjacent sidetracks, i.e., intertrack interference (ITI) while reading the home track. In this letter, we are interested in applying the filtering process to the squeezed tracks before recording to improve the quality of retrieved data. The preprocessing is to reduce the effect of unwanted signals from the sidetracks on the home track. The results show that the SMR system's performance is vastly improved even under the extremely severe effects of the ITI.

Neolamarckia cadamba is an important fast growing tree species used for pulping and wood material in industry for it’s desirable wood properties. As one of the most important content in wood, lignin provides structural integrity, strength, and hydrophobicity to the thickened cell walls and is the major factor contributing to biomass recalcitrance. It does not reduce the palatability of forage grass for animals, but it hinders the isolation of cellulose fibers and the efficient enzymatic depolymerization of cellulose and hemicellulose into fermentable sugars in biorefining processes by limiting the access by hydrolytic enzymes to their polysaccharide substrates. This work focused on analyzing the functions of NcCSE (Caffeoyl Shikimate Esterase, GenBank accession number: MG739672) and NcHCT (Hydroxycinnamoyl Transferase,GenBank accession number: MG739673) in the lignin biosynthetic process in order to improve the potential for utilization of leaves and wood from N. cadamba. The mutant phenotype of cse-2 was dramatically complemented to WT in the stable transgenic lines cse-35S::NcCSE, but overexpression of NcHCT in the cse-2 mutant did not have the same result as cse-35S::NcCSE, providing only partial complementation.

Seed germination and seedling vigor can be affected by environmental cues experienced by the mother plant. However, information about how the maternal environment affects seed quality is scarce in ornamental plants. This study aimed to investigate the effects of two different maternal environments on the seed germination and seedling vigor of Petunia × hybrida under a variety of abiotic stresses. Petunia mother plants were grown in either a greenhouse during the summer months or an indoor controlled-temperature-and-light environment. Collected seeds were subjected to external stressors, including polyethylene glycol (PEG), sodium chloride (NaCl), high temperature, and abscisic acid (ABA), to determine seed germination percentage and seedling vigor. Results indicated that seeds harvested from the mother plants grown in a controlled environment germinated better than seeds harvested from the mother plants grown in the greenhouse when suboptimal germination conditions were applied. Additionally, the seedlings from the controlled maternal environment performed better in both ABA and salinity stress tests than the greenhouse seedlings. Interestingly, the greenhouse seedlings displayed less reactive oxygen species (ROS) damage and lower electrolyte leakage than the controlled environment seedlings under dehydration stress. The difference in germination and seedling vigor of seeds from the two different maternal environments might be due to the epigenetic memory inherited from the mother plants. This study highlighted the strong impact of the maternal environment on seed germination and seedling vigor in Petunia and may assist in high-quality seed production in ornamental plants.

The principal target of this study is to enhance the performance of the 4-level holographic data storage (HDS) systems by using a well-suited modulation code scheme. The HDS system is one of the most promising approaches for storing massive digital data for the next-generation optical data storage systems. However, the performance of retrieving data in the HDS system is severely affected by fatal interference (FI) patterns. The proposed coding design aims to get rid of all FI patterns during the recording procedure with reasonable computational complexity.

Propagation of hops has traditionally been accomplished through vegetative techniques. A more modern technique, micropropagation, can be used to propagate hops and offers several advantages to vegetative techniques. Research examining the use of LED lights in plant production has observed its ability to promote growth in plants through emission of higher light quality, such as enhanced red and blue wavelength discharge. This new 5-page EDIS publication provides information on the use and application of LED lights to enhance leaf area and root length of hops. Written by Chi D. Nguyen, Dominic Vu, Heqiang Huo, and Brian Pearson, and published by the UF/IFAS Environmental Horticulture Department.https://edis.ifas.ufl.edu/ep583

The Asian citrus psyllid (Diaphorina citri Kuwayama) is known to exhibit abdominal color polymorphisms. In the current study, susceptibility to four insecticides was compared among orange/yellow, blue/green and gray/brown color morphs of field collected D. citri. The LD50 values and 95% fiducial limits were quantified for each insecticide and color morph combination and ranged between 0.10 ng/μL (0.06-0.10) and 6.16 ng/μL (3.30-12.50). Second, we measured the detoxification enzyme activity levels of orange/yellow, blue/green and gray/brown color morphs for cytochrome P450, glutathione S-transferase, and general esterase. The mean P450 activity (equivalent units) was significantly lower in gray/brown (0.152 ± 0.006) and blue/green morphs (0.149 ± 0.005) than in the orange/yellow morphs (0.179 ± 0.008). GST activity (μmol/min/mg protein) was significantly lower in the orange/yellow morph (299.70 ±1.24) than gray/brown (350.86 ± 1.19) and blue/green (412.25 ± 1.37) morphs. The mean EST activity (μmol/min/mg protein) was significantly higher in blue/green (416.72 ± 5.12) and gray/brown morphs (362.19 ± 4.69) than in the orange/yellow morphs (282.56 ± 2.93). Additionally, we analyzed the relative expression of assortment genes involved in cuticular melanization and basal immunity. The transcripts of Dopa Decarboxylase and Tyrosine Hydroxylase were expressed higher in blue/green and gray/brown than orange/yellow morphs. The transcription results paralleled the susceptibility of D. citri to organophosphate, neonicotinoid and pyrethroid insecticides. GST and EST activity may also be correlated with low levels of insecticide susceptibility. Cuticular melanization could be a factor for the development of resistance to insecticides among different color morphs.

Bit-patterned media recording (BPMR) has been developed into a technology for the next generation of hard disc drives, which can push area density beyond 1 Tb/in2 for satisfying the ever increasing demand of storing massive amounts of data. One of the major challenges in BPMR systems is 2-D interference that is regarded as a gist of degrading the system performance. From a signal processing viewpoint, 2-D optimal detection schemes are very complicated for 2-D interference channels. In this paper, we propose a twin iterative detection scheme based on 1-D detectors and decoders in order to reduce the complexity. The performance of the proposed scheme is compared to that of a conventional simplified 2-D iterative detection scheme, and the results indicate that the proposed model is better by approximately 1 dB under the effect of 10% track misregistration.

본 연구에서는 베트남 일반은행들의 경쟁력제고를 의사결정의 목적으로 삼고 AHP 계층분석기법을 적용하여 이 문제의 해결을 돕기 위한 모형을 제시하고 있다. 은행 분야 전문가들을 대상으로 항목간 쌍방비교방식으로 이루어진 설문지를 배포하고 회수된 의사결정요소들의 상대적 가중치를 분석한 결과 다음의 세 가지의 주요 결과를 도출하였다. 첫째, 은행의 안전성이 베트남 일반은행들의 경쟁력확보에 있어 가장 중요한 평가기준이며 운용의 효율성, 무형가치의 보유정도 및 영업규모가 그 뒤를 뒤따른다. 둘째, 베트남 일반은행들의 경쟁력제고를 위한 대안으로 건전한 재무상태의 확보가 가장 우선시되어야 한다. 효과적인 경영관리시스템, 전략적 인적자원계획 및 고품질의 제품과 서비스 또한 높은 상대적 가중치를 보인다. 셋째, 건전한 재정확보를 위해서 악성부채 해결이 절대 필요한 것으로 나타났다. 또한, 효과적인 경영관리시스템을 구축하고 고품질의 제품과 서비스를 제공하기 위해서는 신기술의 도입이 매우 중요하다. 아울러 전략적 인적자원계획의 달성을 위해서는 임직원의 자질향상이 절대적으로 필요하다.

This paper designs two protograph LDPC codes with code-rate $R > 1/2$. A simple method using the protograph extrinsic information transfer (PEXIT) to design the codes with a low decoding threshold and the asymptotic weight enumerator (AWE) to evaluate the error floor of the codes is deployed. Simulation results show that the proposed codes have a better error floor than prior art protograph codes and offer higher rate protographs.

This paper presents a new framework of turbo equalization (TE) to overcome 2-D intersymbol interference (2-D ISI) for bit-patterned media recording (BPMR). The BPMR has been developed for the next generation of hard disk drives aiming to extend storage density. One of the main challenges for the system is 2-D ISI, i.e., 1-D ISI from neighbor bits and intertrack interference from adjacent tracks. The conventional TE is the iterative process between an equalizer (or detector) and a decoder. We construct a new scheme of TE where the soft information from the decoder is fed back not only to the equalizer but, at the same time, also to the detector. The proposed scheme is to exploit full advantage of a priori information from the decoder. The results show that the proposed model is approximately 0.4 dB better than the conventional TE solution at 0% track misregistration.

A novel design of de-free k-constraint low-density parity-check (LDPC) code is proposed in this study. The input user data is first converted into a k-constraint code using a nibble replacement method. After that, a guided scrambling (GS) technique and a (4,6) balance code are deployed together to construct de-free channel coded sequences. The designed de-free k constrained code is further combined with the LDPC code such that the modulation constraints are satisfied in both the systematic and parity parts. Simulation results show that the proposed design not only provides an improved bit-error-rate (BER) performance, but also achieves significant dc suppression.

Retrieving original user data from holographic data storage systems is mainly affected by two-dimensional (2D) intersymbol interference; the minimisation of this interference not only improves the system performance, but it also increases the storage density for page-oriented storage systems. An iterative detection that is supported by the readback signal is proposed. The decoded symbols are passed through a 2D partial response target before they are combined with the output of the equaliser, leading to the generation of a refined information source that improves the channel-detection performance. The simulation results show that the proposed structure provides a gain of ∼1–2 dB; furthermore, the combinative quality of the proposed model and a page-based search scheme were analysed as well.

A new model in which an iterative detection is supported by extrinsic information from equalisers is proposed. Furthermore, the system performance involving extrinsic information from an opposite direction one-dimensional soft output Viterbi algorithm is examined. The work is applied to holographic data storage (HDS) systems. The HDS systems are well known as a future storage system because of their extremely large storage capacity and high data transfer rates. However, the system faces two-dimensional interference challenges. The results show that the proposed model vastly improves the performance of the HDS system under severe interference.

This paper presents a 9/12 two-dimensional (2D) modulation code as a way to overcome 2D intersymbol interference (ISI) in bit-patterned media recording (BPMR) systems. BPMR systems are regarded as one of the promising candidates for the attainment of areal density increases that are beyond the capacities of conventional storage systems. The 2D ISI problem significantly degrades the system performance. The results show that the proposed modulation code offers a gain of approximately 2 dB over that of a system without encoding.

This paper presents a scheme that utilizes soft feedback information obtained from a decoder to eliminate detrimental interference in bit-patterned media recording (BPMR) systems. BPMR is a promising technology that can increase the storage area density of magnetic storage systems, but one of the main challenges is to overcome 2-D spatial interference. The performance of the proposed scheme is compared with that of a conventional iterative detection scheme, and the results indicate that the proposed model is better by approximately 1 dB at 20% track misregistration. In particular, the performance of the system is quite superior, allowing the design of systems with higher area densities.