甘蓝DELLA基因家族鉴定及其mRNA在嫁接体中的运输分析

DELLA基因家族参与植物激素信号转导通路的调控,其中GAI(GA insensitive)mRNA还是植物体内长距离运输的信号分子。在全基因组范围内鉴定甘蓝(Brassica oleracea var. capitata) DELLA基因家族成员并分析mRNA运输特性,可为甘蓝DELLA基因家族的开发应用提供基础数据。本研究利用甘蓝基因组数据和转录组数据,在甘蓝中鉴定了5个DELLA基因家族成员(BoRGA1、BoRGA2、BoRGL1、BoRGL2和BoRGL3),但甘蓝基因组缺失了GAI基因。采用劈接法将甘蓝(自交系G27)接穗和菜心(Brassica campestris L. ssp. chinensis var.utilis Tsen et Lee)(四九菜心)砧木嫁接在一起,构建异源嫁接体。对砧木菜心花序轴和对应位置的实生苗菜心花序轴(对照)取样进行转录组测序。在甘蓝/菜心异源嫁接体的砧木菜心花序轴的转录组测序文库中分别鉴定到8、9、3、5、1个来自甘蓝BoRGA1、BoRGA2、BoRGL1、BoRGL2和BoRGL3的外源read。甘蓝DELLA家族基因mRNA运输并没有提高砧木菜心中DELLA家族基因的转录表达水平。相关性分析显示,甘蓝DELLA家族基因mRNA运输效率与其自身的序列和接穗甘蓝中的DELLA家族基因的转录表达水平相关。本研究为深入探究甘蓝DELLA家族基因mRNA运输的分子机制奠定了基础。

Enhancing health-promoting isothiocyanates in Chinese kale sprouts via manipulating BoESP

Glucosinolates(GSLs)are a group of sulfur-containing secondarymetabolites,which are abundant in Brassica vegetables.GSL breakdown products(GBPs),especially isothiocyanates(ITCs)benefit human health.Chinese kale is a native Brassica vegetable in China,and its sprouts are rich in GSLs and nutritional substances.ITCs are the predominant GBPs while alternative products are formed in the presence of specifier proteins.However,fewer ITCs are formed in the sprouts.Epithiospecifier(ESP)promotes the formation of epithionitriles at the expense of ITCs in Arabidopsis,but a systematic study of different isoforms of ESPs in most vegetables is still missing.In this study,changes in the content of GBPs and the precursor GSLs,as well as thiols per plant were monitored during sprout development.The proportions of epithionitriles and ITCs in total GBPs were found to be increased and decreased,respectively.RNA-seq showed enhanced expression of numerous genes involved in GSLs biosynthesis and degradation,as well as sulfur assimilation in sprouts compared to seeds.Four copies of BoESPs were isolated and BoESP2 was the most abundant isoform.Generally,transcription of BoESPs showed a strong response to abscisic acid and gibberellin,and consequently epithionitriles increased under these treatments.Knockdown of BoESP2 expression through virus-induced gene silencing system could effectively increase total ITCs and decrease total epithionitriles.Overall,dynamic GSL metabolic f lux exists in the sprouting period,and the expression of BoESPs determines the pattern of GBPs,suggesting that improving the health-promoting ITCs in Chinese kale sprouts through manipulating BoESPs by metabolic engineering is feasible.

Electric field intensity measurement by using doublet electromagnetically induced transparency of cold Rb Rydberg atoms

We demonstrate a simple method to measure electric field intensity by using doublet electromagnetically induced transparency(EIT) spectra of cold Rb Rydberg atoms, where the frequency of the coupling laser does not need to be locked. Based on the Stark splitting of the Rb Rydberg state, 10D_(3/2), under electric fields and the corresponding calculated polarizabilities, the real electric field intensity is calculated using the difference in radio-frequency diffraction between two acousto-optic modulators, which acts as a frequency criterion that allows us to measure the electrical field without locking the coupling laser. The value measured by this simple method shows a good agreement with our previous work [Opt.Express 29 1558(2021)] where the frequency of the coupling laser needs to be locked with an additional EIT spectrum based on atom vapor and a proportional–integral–differential feedback circuit. Our presented method can also be extended to the measurement of electric field based on hot Rydberg atom vapor, which has application in industry.

Observation of V-type electromagnetically induced transparency and optical switch in cold Cs atoms by using nanofiber optical lattice

Optical nanofiber(ONF)is a special tool to achieve the interaction between light and matter with ultralow power.In this paper,we demonstrate V-type electromagnetically induced transparency(EIT)in cold atoms trapped by an ONFbased two-color optical lattice.At an optical depth of 7.35,90%transmission can be achieved by only 7.7 pW coupling power.The EIT peak and linewidth are investigated as a function of the coupling optical power.By modulating the pWlevel control beam of the ONF-EIT system in sequence,we further achieve efficient and high contrast control of the probe transmission,as well as its potential application in the field of quantum communication and quantum information science by using one-dimensional atomic chains.

Optomechanical feedback cooling of a 5 mm long torsional mode

We report three orders of magnitude optical cooling of the fundamental torsional mode of a 5 mm long,550 nm diameter optical nanofiber.The rotation of the nanofiber couples to the polarization of guided laser fields.We use a weak laser probe to monitor the rotation and use feedback to modulate the polarization of an auxiliary drive laser providing torque.Our results present a tool for the optomechanical control of large-scale torsional resonators,with metrological applications and potential implications for studying macroscopic objects in quantum states.

Torsional optomechanical cooling of a nanofiber

We demonstrate the optomechanical cooling of a tapered optical nanofiber by coupling the polarization of light to the mechanical angular momentum of the system. The coupling is enabled by birefringence in the fiber and does not make use of an optical resonator. We find evidence for cooling in the distribution of thermally driven amplitude fluctuations and the noise spectrum of the torsional modes. Our proof-of-principle demonstration shows cavity-less cooling of the torsional degree of freedom of a macroscopically extended nanofiber.

Absorption saturation measurement using the tapered optical nanofiber in a hot cesium vapor

We report the observation of ultralow-power absorption saturation in a tapered optical fiber(TOF) mounted in a hot cesium(Cs) vapor in a vacuum chamber. The small optical mode area of TOF produces a great influence on optical properties, allowing optical interactions with nanowatt-level power. The comparison of transmission characteristics for the TOF system and free-space vapor is investigated at different input power and atomic density. The unique performance of the Cs-TOF system makes it a promising candidate in resonant nonlinear optical applications with ultralow power.

Dark state atoms trapping in a magic-wavelength optical lattice near the nanofiber surface

We report the experimental realization of dark state atoms trapping in a nanofiber optical lattice.By applying the magicwavelength trapping potentials of cesium atoms,the AC Stark shifts are strongly suppressed.The dark magneto-optical trap efficiently transfers the cold atoms from bright (6S_(1/2),F=4) into dark state (6S_(1/2),F=3) for hyperfine energy levels of cesium atoms.The observed transfer efficiency is as high as 98%via saturation measurement.The trapping lifetime of dark state atoms trapped by a nanofiber optical lattice is also investigated,which is the key element for realizing optical storage.This work contributes to the manipulation of atomic electric dipole spin waves and quantum information storage for fiber networks.