Our official account iPlants will summarize the research teams from different universities and institutes in China, and the first one is the Chinese Artemisia research. Tang kexuan team of Shanghai Jiaotong University published 57 papers on Artemisia annua research! 2 nature, 2 Science and 3 nature subjournals, the team has made a series of progress in the research of photosynthetic light trapping complex! It took 17 years and published more than 10 papers! Zhu health group established a complete path of active DNA demethylation in plants! System summary! Etc.
Today we are concerned about Zhang Xiaolan's research group from China Agricultural University, which is mainly engaged in the research of cucumber plant type and fruit shape development. In the past two years (April 2018 to April 2020), 12 corresponding author articles have been published, including curr opin plant Biol (February 2019), plant cell (April 2019), PLoS Biol (March 2020), development (July 2019; March 2020), PNAs (August 2019), front plant SCI (February 2020; January 2018) plant J (August 2018); May 2018), new phytol (April 2018), and Biochem Biophys res commun (may 2018). It is worth noting that the research group mainly focuses on cucumbers. It is not easy to have such a high output! Details are as follows:
The representative works are explained as follows:
1.2018 CsLFY is required for shoot meristem maintenance via interaction with WUSCHEL in Cucumber (Cucumis sativus) was published online by New Phytol in April 2018.
Cucumber (Cucumis sativus) is an important agronomic vegetable with uncertain growth habits, in which leaves are produced from stem tip meristem (SAM) and unisexual flowers (male or female flowers) are produced from leaf axils (see figure below).
Leaf (LFY) and its homologues have been shown to play an important role in promoting flower development and branching. This study combined molecular biology, developmental biology and biochemical methods to explore the biological function of cslfy homologous gene in cucumber. For the first time, cslfy was found to be expressed in Sam, floral meristem and floral organ primordium. In addition, the heterotopic expression of cslfy in Arabidopsis can restore the phenotype of lfy-5 mutant. Furthermore, RNA interference (RNAi) knockout of cslfy resulted in the early interruption of defective branch development and cucumber leaf germination. In the cslfy RNAi line, the transcription of cswus and cslfy target genes (including csap3 and cum1) was significantly reduced. Further biochemical analysis showed that cslfy could interact with cswus in cucumber. Therefore, this study shows that the interaction between cslfy and cswus in Cucumber regulates the function of bud meristem maintenance, and promotes flower development by activating csap3 and cum1 in Cucumber (see the figure below).
Paper link: https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/nph.14954
2. In May 2018, plant J published a research article entitled "csspl functions as an adapter between HD-Zip III and cswus transcription factors regulating anther and ovule development in Cucumis sativus (cucumber)" online.
In this study, the spontaneous mutant MF was obtained by screening the mutants with reproductive growth defects, which showed male sterility and low female fertility. Compared with the wild type (WT), the stamens of MF had no pollen formation. In addition, ovary development is deficient and ovule is absent, which is similar to Arabidopsis SPL mutant.
Further knockout of CsSPL will reduce the fertility of male and female, lead to pollen deformity and inhibit ovule development. Importantly, csspl interacts directly with cswus (WUSCHEL) in nucellus and yabby family genes in globin, and regulates the expression of cswus positively. At the same time, csphb (phabulosa), the HD-Zip III gene specifically expressed in nucellus, promotes the expression of csspl by combining with csspl promoter. As a result, CSPL acts as an adapter connecting csphb and cswus functions, coordinating the sexual organ development of plants. In addition, the accumulation of auxin in the reproductive organs of csspl knockdown plants decreased. Biochemical analysis further showed that csspl stimulated the expression of aux in response factor 3 (csarf3) and was positively regulated by csarf13 during the development of reproductive organs, indicating the sequential interaction between csspl and auxin signal components in coordinating anther and ovule development (see figure below).
Paper link: https://onlinelibrary.wiley.com/doi/pdf/10.1111/tpj.13877
3. In February 2019, current operation in plant biology published an online review article entitled "molecular basis of cucumber fruit home indication".
Cucumber (Cucumis sativus L.) is one of the most important vegetable crops in the world. Compared with the wild ancestors of small, bitter and juicy fruits, domesticated cucumbers showed significant changes in fruit appearance, size and flavor. Understanding the molecular basis of domestication related traits can provide insights into fruit evolution and make crop breeding more effective. In this review, we reviewed the latest progress in the genetic basis of fruit morphological characteristics (female, fruit, wart, size, color and carpel development) and sensory characteristics (bitter taste) during cucumber domestication.
4. In April 2019, the plant cell published a research paper entitled "a functional allele of csul1 regulations fruit length through expressing cssup and inhibiting auxiliary transport in cucumber" online.
The fruits of C. sativus var. hardwickii are small and round, with a length of about 3-5 cm, while that of C. sativus var. hardwickii is more than 35 cm. In the process of cucumber cultivation and acclimation, the key regulatory factors and their molecular mechanism that affect the difference of cucumber fruit length are still poorly understood.
In this study, two csful1 alleles, named csful1a and csful1c respectively, were found in 150 cucumbers with different fruit length. Among them, csful1a is specific in the East Asian type long fruit cucumber, while csful1c is in the wild, semi wild type and other cultivated cucumbers. Using the stable genetic transformation system of cucumber, it was found that the interference expression of csful1a resulted in the fruit becoming longer, and the overexpression of csful1a resulted in the fruit becoming shorter, while the expression change of csful1c did not affect the fruit length. Therefore, csful1a is an acquired allele, which can inhibit the elongation of cucumber fruit.
In order to further reveal the molecular mechanism of csful1a participating in the development of cucumber fruit, we found that csful1a could directly inhibit the expression of cssup gene and regulate cell division and expansion, and csful1a could directly inhibit the expression of two auxin transporter genes, cspin1 and cspin7, so as to reduce auxin accumulation. The results not only provide a reference for revealing the genetic regulation mechanism of cucumber fruit length, but also provide an important target gene for molecular design and breeding of cucumber fruit length.
Paper link: http://www.plantcell.org/content/plantcell/31/6/1289.full.pdf
5. In July 2019, development magazine published a research paper entitled "cstfl1 inbits determine growth and terminal flower formation through interaction with csnot2a in cucumber" online.
Cucumbers are annual creeping or climbing herbs of Cucurbitaceae muskmelon, which are widely planted in temperate and tropical areas. They are widely cultivated in many areas of China, and they are cultivated in greenhouses or plastic greenhouses. The phenomenon of "flower topping" often occurs in the growing process of cucumbers in greenhouses. Cucumber flower topping, also known as flower holding head, is a common physiological obstacle in cucumber production in greenhouse. It is usually manifested as the shortening of internode near the growth point, the emergence of male and female hybrid flower clusters without the formation of heart leaves, in the shape of flower holding head. Flower topping usually occurs at the early stage of fruit bearing, which has a great influence on the yield and quality of cucumber. But we know little about its molecular mechanism at present!
In this study, cstfl1, a gene controlling flower topping in cucumber, was identified by map based cloning. It was found that in a mutant material with limited growth, it was caused by the non synonymous SNP of this gene. Cstfl1 was expressed in the apical meristem, lateral meristem and proximal region of young stem. The ectopic expression of cstfl1 can restore the flower topping phenotype in Arabidopsis tfl1-11 mutant and delay flowering in wild type Arabidopsis. On the other hand, knockout of cstfl1 resulted in certain growth and terminal flower formation in cucumber. Biochemical analysis showed that cstfl1 interacted with csnot2a protein and further formed three protein flowering activation complexes (cstfl1-csnot2a-csfddp) with FDP. CSFT interacts directly with csnot2a and CSFD, while CSFD interacts with two 14-3-3 proteins. Therefore, this study shows that the interaction between cstfl1 and CSFT competition and csnot2a csfdp can inhibit the growth and flower formation of cucumber.
Paper link:
https://dev.biologists.org/content/develop/146/14/dev180166.full.pdf
6.2019 in August, PNAS online published the research paper entitled "CsBRC1 inhibits axillary bud outgrowth by directly repressing the auxin efflux carrier CsPIN3 in cucumber".
Branch branching is an important agronomic character, which directly determines plant structure and affects crop productivity. In order to improve the yield and quality of crops, it is necessary to remove the axillary branches manually during cucumber production. As we all know, auxin is the signal molecule of apical dominance, and indirectly acts as the inhibitor of lateral bud growth. Bronched1 / cycloidea / PCF (TCP) family gene bronched1 (brc1) has been proved to be the central integration of multiple environmental and developmental signals, which plays a local role to inhibit branch branching. However, the direct molecular link between auxin and brc1 remains elusive.
In this study, it was found that cucumber branched1 (csbrc1) was expressed in axillary buds, and showed higher expression level in cultivated cucumber than its wild ancestors. The decrease of csbrc1 by RNAi resulted in the increase of bud growth and the decrease of auxin accumulation in buds. Further studies have shown that csbrc1 directly binds to pin-formed (cspin3) and negatively regulates its expression in vitro and in vivo. The increased expression of cspin3 driven by the csbrc1 promoter led to the decrease of auxin level in the lateral buds of highly branched cucumber. Therefore, the results showed that csbrc1 inhibited the growth of lateral buds and auxin accumulation in axillary buds of Cucumber by inhibiting the function of cspin3 directly, which provided breeding strategies for varieties with different degrees of branch growth in different cucumber production systems.
Paper link:
https://www.pnas.org/content/pnas/early/2019/08/06/1907968116.full.pdf
7. In March 2020, PLoS Biology published a research paper entitled "csivp functions in vascular development and down mildew resistance in cucumber" online. This paper revealed that the bHLH transcription factor csivp of cucumber directly combines with the vascular development regulators csyab5 and CSBP At the same time, csivp and csnimin1 protein, a signal transduction pathway of salicylic acid, interact directly to regulate the resistance of cucumber downy mildew.
Crop domestication promotes the development of agriculture and human society. Artificial selection makes cultivated varieties have good agronomic characters, but they often lose the resistance. When plants are infected with pathogens, the cost of defense response is the reduction of growth and reproduction ability. Although the basis of domestication has been studied, the underlying mechanism of coordinated regulation of development and disease resistance is still unclear. Vascular influences the morphological development of plant organs, and also participates in the process of plant disease resistance through the transport of hormones, proteins and RNA. At present, no vascular regulators have been confirmed to be directly involved in plant resistance.
The research group