Plant Biotechnology Journal最新文献

{"title":"Characterization of a tomato chlh mis-sense mutant reveals a new function of ChlH in fruit ripening","authors":"Dawei Xu, Li Lin, Xiaorui Liu, MeLongying Wangzha, Xiaoqing Pang, Liping Feng, Bingbing Wan, Guo-Zhang Wu, Jingquan Yu, Jean-David Rochaix, Bernhard Grimm, Ruohe Yin","doi":"10.1111/pbi.14548","DOIUrl":"https://doi.org/10.1111/pbi.14548","url":null,"abstract":"Tomato fruit ripening is a complex developmental process that is important for fruit quality and shelf life. Many factors, including ethylene and several key transcription factors, have been shown to play important roles in the regulation of tomato fruit ripening. However, our understanding of the regulation of tomato fruit ripening is still limited. Here, we describe <i>mut26</i>, an EMS-induced tomato (<i>Solanum lycopersicum</i>) mutant that exhibits chlorophyll-deficient phenotypes in various organs, including fruits. Genetic mapping and functional analyses revealed that a single-nucleotide substitution and a corresponding Pro398–&gt;Ser mis-sense mutation in <i>SlChlH</i> (<i>GENOMES UNCOUPLED 5, GUN5</i>), which encodes the H subunit of magnesium chelatase, are responsible for the defects in the <i>mut26</i> strain. Transcript analyses towards the expression of many <i>SlPhANGs</i> revealed that <i>mut26</i> is defective in plastid retrograde signalling during tomato fruit ripening initiation, namely the transition from mature green to breaker stage. <i>mut26</i> exhibits delayed progression of fruit ripening characterized by reduced fruit ethylene emission, increased fruit firmness, reduced carotenoid content and delayed plastid conversion from chloroplast to chromoplast. Given that fruit ripening requires signalling from plastids to nucleus, these data support the hypothesis that GUN5-mediated plastid retrograde signalling promotes tomato fruit ripening. We further showed that the delayed fruit ripening of <i>mut26</i> is not likely caused by reduced chlorophyll content. Taken together, we identified a new function of SlChlH in the promotion of tomato fruit ripening and ethylene biosynthesis, suggesting that GUN5-mediated plastid retrograde signalling plays a promotive role in tomato fruit ripening.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"62 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The transcription factor OsNAC25 regulates potassium homeostasis in rice","authors":"Chen Wang, Shaowen Song, Jun Fu, Kai Wang, Xuan Chen, Bin Bo, Zhe Chen, Linan Zhang, Lin Zhang, Xiaohui Wang, Niwen Tang, Xiangrong Tian, Liangbi Chen, Sheng Luan, Yuanzhu Yang, Dandan Mao","doi":"10.1111/pbi.14550","DOIUrl":"https://doi.org/10.1111/pbi.14550","url":null,"abstract":"Over-application of potassium (K) fertilizer in fields has a negative impact on the environment. Developing rice varieties with high KUE will reduce fertilizer for sustainable agriculture. However, the genetic basis of KUE in a more diverse and inclusive population remains largely unexplored. Here, we show that the transcription factor OsNAC25 enhances K⁺ uptake and confers high KUE under low K⁺ supply. Disruption of <i>OsNAC25</i> by CRISPR/Cas9-mediated mutagenesis led to a considerable loss of K⁺ uptake capacity in rice roots, coupled with reduced K⁺ accumulation in rice and severe plant growth defects under low- K⁺ conditions. However, the overexpression of <i>OsNAC25</i> enhanced K⁺ accumulation by regulating proper K⁺ uptake capacity in rice roots. Further analysis displayed that <i>OsNAC25</i> can bind to the promoter of <i>OsSLAH3</i> to repress its transcription in response to low- K⁺ stress. Nucleotide diversity analyses suggested that OsNAC25 may be selected during japonica populations' adaptation of low K⁺ tolerance. Natural variation of <i>OsNAC25</i> might cause differential expression in different haplotype varieties, thus conferring low K⁺ tolerance in the Hap 1 and Hap 4 -carrying varieties, and the japonica allele <i>OsNAC25</i> could enhance low K⁺ tolerance in <i>indica</i> variety, conferring great potential to improve <i>indica</i> low K⁺ tolerance and grain development. Taken together, we have identified a new NAC regulator involved in rice low K⁺ tolerance and grain development, and provide a potential target gene for improving low K⁺ tolerance and grain development in rice.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"86 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering a robust Cas12i3 variant-mediated wheat genome editing system","authors":"Wenxue Wang, Lei Yan, Jingying Li, Chen Zhang, Yubing He, Shaoya Li, Lanqin Xia","doi":"10.1111/pbi.14544","DOIUrl":"https://doi.org/10.1111/pbi.14544","url":null,"abstract":"Wheat (<i>Triticum aestivum</i> L., 2<i>n</i> = 6<i>x</i> = 42, AABBDD) is one of the most important food crops in the world. CRISPR/Cas12i3, which belongs to the type V-I Cas system, has attracted extensive attention recently due to its smaller protein size and its less-restricted canonical ‘TTN’ protospacer adjacent motif (PAM). However, due to its relatively lower editing efficacy in plants and the hexaploidy complex nature of wheat, Cas12i3/Cas12i3-5M-mediated genome editing in wheat has not been documented yet. Here, we report the engineering of a robust Cas12i3-5M-mediated genome editing system in wheat through the fusion of T5 exonuclease (T5E) in combination with an optimised crRNA expression strategy (Opt). We first showed that fusion of T5E, rather than ExoI, to Cas12i3-5M increased the gene editing efficiencies by up to 1.34-fold and 3.87-fold, compared to Cas12i3-5M and Cas12i3 in HEK293T cells, respectively. However, its editing efficiency remains low in wheat. We then optimised the crRNA expression strategy and demonstrated that Opt-T5E-Cas12i3-5M could enhance the editing efficiency by 1.20- to 1.33-fold and 4.05- to 7.95-fold in wheat stable lines compared to Opt-Cas12i3-5M and Opt-Cas12i3, respectively, due to progressive 5′-end resection of the DNA strand at the cleavage site with increased deletion size. The Opt-T5E-Cas12i3-5M enabled an editing efficiency ranging from 60.71% to 90.00% across four endogenous target genes in stable lines of three elite Chinese wheat varieties. Together, the developed robust Opt-T5E-Cas12i3-5M system enriches wheat genome editing toolkits for either biological research or genetic improvement and may be extended to other important polyploidy crop species.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"1216 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The OsNL1-OsTOPLESS2-OsMOC1/3 pathway regulates high-order tiller outgrowth in rice","authors":"Xin Liu, Feng Zhang, Ziqi Xun, Jiale Shao, Wenfan Luo, Xiaokang Jiang, Jiachang Wang, Jian Wang, Shuai Li, Qibing Lin, Yulong Ren, Huixian Zhao, Zhijun Cheng, Jianmin Wan","doi":"10.1111/pbi.14547","DOIUrl":"https://doi.org/10.1111/pbi.14547","url":null,"abstract":"Tiller is an important factor in determining rice yield. Currently, researches mainly focus on the outgrowth of low-order tiller (LOT), while the regulation mechanism of high-order tiller (HOT) outgrowth has remained unknown. In this study, we detected one <i>OsNL1</i> mutant, <i>nl1</i>, exhibiting HOT numbers increase, and found that OsNL1 interacts with OsTOPLESS2, which was mediated by the core motif of nine amino acids VDCTLSLGT within the HAN domain of OsNL1. The <i>topless2</i> mutant exhibits similar HOT number increase as in the <i>nl1</i>. Through ChIP-seq analysis, we revealed that OsNL1 recruits OsTOPLESS2 to conduct histone deacetylation in the promoters of <i>OsMOC1</i> and <i>OsMOC3</i> to regulate HOT outgrowth. Moreover, we showed that the HAN domain is essential for OsNL1 function as a repressor. In summary, our study reveals partial mechanism of HOT outgrowth in rice and deciphers the molecular biology function of the HAN domain. This will contribute to the comprehensive understanding of tiller outgrowth and the role of HAN-domain-containing genes.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"12 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification and knockout of rhamnose synthase CiRHM1 enhances accumulation of flavone aglycones in chrysanthemum flower","authors":"Chang Luo, Jiayi Luo, Mingzheng Han, Zhenzhen Song, Yahui Sun, Yaqin Wang, Yafei Zhao, Conglin Huang, Junping Gao, Bo Hong, Chao Ma","doi":"10.1111/pbi.14556","DOIUrl":"https://doi.org/10.1111/pbi.14556","url":null,"abstract":"&lt;p&gt;Flavonoids play critical roles in plant adaptation to environmental changes and are valuable medicinal resources (Chagas &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2022&lt;/span&gt;). Flavonoids are predominantly found in glycosylated forms, which exhibit increased structural complexity, solubility and stability. However, the aglycone forms of flavonoids exhibit greater antioxidant capacity and bioavailability (Xie &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2022&lt;/span&gt;). Enhancing the content of flavonoid aglycones in crops can improve their nutritional value and health benefits for humans.&lt;/p&gt;\u0000&lt;p&gt;In plants, UDP-rhamnose serves as a key sugar donor in flavonoid glycosylation, synthesized from UDP-glucose via the enzyme rhamnose synthase (RHM). In Arabidopsis (&lt;i&gt;Arabidopsis thaliana&lt;/i&gt;), mutations in the &lt;i&gt;RHM1&lt;/i&gt; lead to significant reduction in rhamnosylated flavonols (Saffer and Irish, &lt;span&gt;2018&lt;/span&gt;). However, as Arabidopsis lacks flavone synthase and flavones, the impacts of UDP-rhamnose on flavone aglycone or glycoside biosynthesis are unknown.&lt;/p&gt;\u0000&lt;p&gt;&lt;i&gt;Chrysanthemum indicum&lt;/i&gt;, a notable medicinal plant, has been used in traditional Chinese medicine for over 2000 years (He &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2016&lt;/span&gt;). The dried flowers of &lt;i&gt;C. indicum&lt;/i&gt;, known as ‘Yejuhua’ in the &lt;i&gt;Pharmacopoeia of the People's Republic of China&lt;/i&gt; (2020 edition), are recognized for their anti-inflammatory, antioxidant, antimicrobial, anticancer and immunomodulatory properties (Xie &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2012&lt;/span&gt;). These pharmaceutical effects are largely attributed to the high flavone content, particularly compounds like apigenin, luteolin and their derivatives (Shao &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2020&lt;/span&gt;). Previous studies have shown significant variations in morphology and metabolic composition among different eco-geographic populations (ecotypes) of &lt;i&gt;C. indicum&lt;/i&gt; in China, influencing their medicinal and nutritional value (Fang &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2012&lt;/span&gt;).&lt;/p&gt;\u0000&lt;p&gt;To explore the natural variation of flavones in &lt;i&gt;C. indicum&lt;/i&gt;, we collected ecotypes from various regions across China, and quantified the major bioactive flavone, apigenin, in the flowers using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS). A metabolite-based genome-wide association study (mGWAS) was performed on 72 ecotypes exhibiting distinct apigenin content (Figure 1a; Dataset S1). The association analysis showed that the natural variation in apigenin content across these ecotypes was governed by two loci located on chromosomes 2 and 9 (Figure 1b–c). Within the locus on chromosome 2, we identified a &lt;i&gt;TREHALOSE-6-PHOSPHATE SYNTHASE1&lt;/i&gt; gene (&lt;i&gt;CiTPS1&lt;/i&gt;, Cse_sc000461.1_g010.1) and &lt;i&gt;CiRHM1&lt;/i&gt; (Cse_sc000461.1_g020.1) (Figure 1b; Table S1). Collinearity analysis indicated that the &lt;i&gt;TPS1-RHM1&lt;/i&gt; gene cluster is conserved among dicotyledonous plants (Figure S1). RNA-seq of 18 ecotypes showed that the expression of &lt;i&gt;CiRHM1&lt;/i&gt; was negatively correlated with apigenin content (Figure 1d, Tab","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"1 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TmCOP1-TmHY5 module-mediated blue light signal promotes chicoric acid biosynthesis in Taraxacum mongolicum","authors":"Qun Liu, Zhiqing Wu, Xiwu Qi, Hailing Fang, Xu Yu, Li Li, Zequn Chen, Jie Wu, Yugang Gao, Guoyin Kai, Chengyuan Liang","doi":"10.1111/pbi.14542","DOIUrl":"https://doi.org/10.1111/pbi.14542","url":null,"abstract":"Chicoric acid, a phenolic compound derived from plants, exhibits a range of pharmacological activities. Light significantly influences the chicoric acid biosynthesis in <i>Taraxacum mongolicum</i>; however, the transcriptional regulatory network governing this process remains unclear. A combined analysis of the metabolome and transcriptome revealed that blue light markedly enhances chicoric acid accumulation compared to red light. The blue light-sensitive transcription factor ELONGATED HYPOCOTYL5 (HY5) is closely associated with multiple core proteins, transcription factors and chicoric acid synthase genes involved in light signalling. Both <i>in vivo</i> and <i>in vitro</i> experiments demonstrated that TmHY5 directly regulates several chicoric acid biosynthetic genes, including <i>TmPAL3</i>, <i>Tm4CL1</i> and <i>TmHQT2</i>. Additionally, TmHY5 promotes the accumulation of luteolin and anthocyanins by increasing the expression of <i>TmCHS2</i> and <i>TmANS2</i>. The E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) forms a protein complex with TmHY5, significantly inhibiting chicoric acid biosynthesis. Blue light inhibits TmCOP1-TmHY5 complex protein formation while enhancing the expression levels of <i>TmCOP1</i> through TmHY5. Furthermore, TmHY5 elevates the expression levels of <i>TmbZIP1</i>, which indirectly activates <i>Tm4CL1</i> expression. <i>In vivo</i>, TmCOP1 directly inhibits the expression of the TmHY5-Tm4CL1 complex. Therefore, we speculate that TmCOP1-TmHY5-mediated blue light signalling effectively activates chicoric acid biosynthesis, providing a foundation for the application of blue light supplementation technology in industrial production.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"12 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rational design of azo-aminopyrimidine derivatives as the potent lepidoptera-exclusive chitinase inhibitors","authors":"Baokang Ding, Shujie Ma, Meiling Yang, Quanguo Zhang, Xiujia Hua, Jiahao Zhang, Shenmeng Bai, Lihui Zhang, Jingao Dong, Shengqiang Shen, Lili Dong","doi":"10.1111/pbi.14538","DOIUrl":"https://doi.org/10.1111/pbi.14538","url":null,"abstract":"<i>Ostrinia furnacalis</i> (<i>O. furnacalis</i>) is a commonly occurring agricultural pest that can severely impact corn yield and quality. Therefore, establishing and implementing effective control methods against <i>O. furnacalis</i> are of great significance. Chemical insecticides remain the most effective means to mitigate the damage caused by <i>O. furnacalis</i>. With the increasing resistance of <i>O. furnacalis</i> to insecticides, it is imperative to identify and develop compounds with novel mechanisms of action and high safety. The chitinase O<i>f</i>Chi-h, identified and characterized in <i>O. furnacalis</i>, has been recognized as a potential insecticide target. In this study, a series of azo-aminopyrimidine analogues were synthesized as O<i>f</i>Chi-h inhibitors employing rational molecular optimization. Among them, compounds <b>9b</b>, <b>10a</b> and <b>10g</b> exhibited <i>K</i>_i values of 23.2, 19.4, and 43.2 nM against O<i>f</i>Chi-h, respectively. Molecular docking studies were carried out to explore the molecular basis for the high efficacy of these compounds and O<i>f</i>Chi-h. In addition, the morphological changes of the cuticle in inhibitor-treated <i>O. furnacalis</i> larvae were assessed using scanning electron microscopy. Furthermore, the target compounds were assayed in leaf dipping and pot experiments, with compound <b>10a</b> exhibiting greater insecticidal activity against <i>Plutella xylostella</i> (<i>P. xylostella</i>) and <i>O. furnacalis</i> than diflubenzuron and chlorbenzuron. At the same time, the toxicity of these compounds to natural enemies <i>Trichogramma ostriniae</i> and rats was negligible. The present study demonstrates that the azo-aminopyrimidine skeleton can be used as a novel, low-cost scaffold for developing insect chitinolytic enzyme inhibitors, with the potential to be utilized as new environmentally friendly insecticides.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"9 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Meiotic crossovers revealed by differential visualization of homologous chromosomes using enhanced haplotype oligo-painting in cucumber","authors":"Qinzheng Zhao, Zhenhui Xiong, Chunyan Cheng, Yuhui Wang, Xianbo Feng, Xiaqing Yu, Qunfeng Lou, Jinfeng Chen","doi":"10.1111/pbi.14546","DOIUrl":"https://doi.org/10.1111/pbi.14546","url":null,"abstract":"The interaction dynamics of homologous chromosomes during meiosis, such as recognition, pairing, synapsis, recombination, and segregation are vital for species fertility and genetic diversity within populations. Meiotic crossover (CO), a prominent feature of meiosis, ensures the faithful segregation of homologous chromosomes and enriches genetic diversity within a population. Nevertheless, visually distinguishing homologous chromosomes and COs remains an intractable challenge in cytological studies, particularly in non-model or plants with small genomes, limiting insights into meiotic dynamics. In the present study, we developed a robust and reliable enhanced haplotype oligo-painting (EHOP) technique to image small amounts of oligos, enabling visual discrimination of homologous chromosomes. Using EHOP developed based on sequence polymorphisms and reconstructed oligonucleotides, we visually distinguished parental and most recombinant chromosomes in cucumber F₁ hybrids and F₂ populations. Results from EHOP revealed that meiotic CO events preferentially occur in the 30–60% intervals of chromosome arms with lower sequence polymorphisms and significant recombination bias exists between cultivated and ancestral chromosomes. Due to the occupation of extensive heterochromatin occupancy, it is not yet possible to precisely identify the meiotic COs present in the central portion of chr2 and chr4. Notably, CO accessibility was universally detected in the cytological centromere region in F₂ populations, a feature rarely observed in crops with large genomes. EHOP demonstrated exceptional performance in distinguishing homologous chromosomes and holds significant potential for broad application in studying homologous chromosome interactions.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"21 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142804519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Manipulation of the microRNA172–AP2L2 interaction provides precise control of wheat and triticale plant height","authors":"Chaozhong Zhang,&nbsp;Joshua Hegarty,&nbsp;Mariana Padilla,&nbsp;David M. Tricoli,&nbsp;Jorge Dubcovsky,&nbsp;Juan M. Debernardi","doi":"10.1111/pbi.14499","DOIUrl":"10.1111/pbi.14499","url":null,"abstract":"&lt;p&gt;The &lt;i&gt;REDUCED HEIGHT&lt;/i&gt; (&lt;i&gt;RHT&lt;/i&gt;) dwarfing alleles &lt;i&gt;Rht-B1b&lt;/i&gt; and &lt;i&gt;Rht-D1b&lt;/i&gt; were essential in the ‘Green Revolution’. The &lt;i&gt;RHT1&lt;/i&gt; gene encodes a DELLA protein, which participates in the gibberellin (GA) growth-stimulating pathway (Peng &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;1999&lt;/span&gt;), and truncations of this protein are responsible for the GA-insensitive semi-dwarf &lt;i&gt;Rht1b&lt;/i&gt; alleles (Van De Velde &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2021&lt;/span&gt;). The growth-repressing effect of &lt;i&gt;Rht1b&lt;/i&gt; alleles optimized plant height, reduced lodging and improved harvest index, but also reduced above-ground biomass and coleoptile length, limiting sowing depth and access to deeper soil moisture (Ellis &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2004&lt;/span&gt;). This has triggered the search for GA-sensitive dwarfing genes with fewer negative pleiotropic effects.&lt;/p&gt;&lt;p&gt;Plant height in grasses is regulated by a complex genetic network, which includes the conserved microRNA172 (miR172)–&lt;i&gt;APETALA2&lt;/i&gt;-like (&lt;i&gt;AP2L&lt;/i&gt;) module (Patil &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2019&lt;/span&gt;; Zhu and Helliwell, &lt;span&gt;2011&lt;/span&gt;). In wheat, miR172 expression is induced during the reproductive transition and regulates flowering time, plant height and both spike and floret development by repressing the expression of &lt;i&gt;AP2L&lt;/i&gt; genes (Debernardi &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2017&lt;/span&gt;). Reduction of miR172 activity in the semi-dwarf tetraploid wheat variety ‘Kronos’ (&lt;i&gt;Rht-B1b&lt;/i&gt;) using a transgenic target mimicry (MIM172) approach delayed reproductive transition a few days and generated shorter plants with more compact spikes (Debernardi &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2017&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;Among the four &lt;i&gt;AP2L&lt;/i&gt; genes targeted by miR172 in wheat, &lt;i&gt;AP2L2&lt;/i&gt; and &lt;i&gt;AP2L5&lt;/i&gt; regulate flowering transition, stem elongation and spike development (Debernardi &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2020&lt;/span&gt;). Point mutations in the miR172 target site of the &lt;i&gt;AP2L&lt;/i&gt; genes reduce miR172 activity and generate resistant alleles designated hereafter as &lt;i&gt;rAp2l&lt;/i&gt;. An &lt;i&gt;rAp2l&lt;/i&gt;-&lt;i&gt;A5&lt;/i&gt; allele originated the domestication gene &lt;i&gt;Q&lt;/i&gt; and the free-threshing wheats (Debernardi &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2017&lt;/span&gt;). Additional mutations in the miR172 target site of &lt;i&gt;Q&lt;/i&gt; or in the homeolog &lt;i&gt;AP2L-D5&lt;/i&gt; result in plants with reduced height but, unfortunately, with associated spike defects (Greenwood &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2017&lt;/span&gt;; Zhao &lt;i&gt;et al&lt;/i&gt;., &lt;span&gt;2018&lt;/span&gt;). In this study, we explore the effects of chemically induced alleles &lt;i&gt;rAp2l-A2&lt;/i&gt; from tetraploid and &lt;i&gt;rAp2l-B2&lt;/i&gt; from hexaploid wheat (Figure S1a) as well as multiple new CRISPR-induced alleles. All materials and methods are described in the Materials and Methods in Appendix S1.&lt;/p&gt;&lt;p&gt;The &lt;i&gt;rAp2l-A2&lt;/i&gt; EMS-mutation in the semi-dwarf Kronos reduced stem length by 21%, whereas the introgression of the &lt;i&gt;rAp2l-B2&lt;/i&gt; allele into Kronos or Kronos-&lt;i&gt;rAp2l-A2&lt;/i&gt; backgrounds, reduced stem length by 43–45% (Figure S1a–c, Data S1). We next used CRISPR-Cas9 with a gRNA specifically","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"23 2","pages":"333-335"},"PeriodicalIF":10.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/pbi.14499","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142809685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinct effects of PTST2b and MRC on starch granule morphogenesis in potato tubers","authors":"Anton Hochmuth,&nbsp;Matthew Carswell,&nbsp;Aaron Rowland,&nbsp;Danielle Scarbrough,&nbsp;Lara Esch,&nbsp;Nitin Uttam Kamble,&nbsp;Jeffrey W. Habig,&nbsp;David Seung","doi":"10.1111/pbi.14505","DOIUrl":"10.1111/pbi.14505","url":null,"abstract":"<p>The molecular mechanisms underpinning the formation of the large, ellipsoidal starch granules of potato tuber are poorly understood. Here, we demonstrate the distinct effects of PROTEIN TARGETING TO STARCH2b (PTST2b) and MYOSIN RESEMBLING CHLOROPLAST PROTEIN (MRC) on tuber starch granule morphology. A gene duplication event in the <i>Solanaceae</i> resulted in two PTST2 paralogs (PTST2a and PTST2b). PTST2b is expressed in potato tubers, and unlike PTST2a, it had no detectable interaction with STARCH SYNTHASE 4. MRC expression was detectable in leaves, but not in tubers. Using transgenic potato lines in the variety Clearwater Russet, we demonstrate that MRC overexpression leads to the formation of granules with aberrant shapes, many of which arise from multiple initiation points. Silencing PTST2b led to the production of striking near-spherical granules, each arising from a single, central initiation point. Contrary to all reported PTST2 mutants in other species, we observed no change in the number of granules per cell in these lines, suggesting PTST2b is specifically involved in the control of starch granule shape. Starch content and tuber yield per plant were not affected by PTST2b silencing, but MRC overexpression led to strong decreases in both parameters. Notably, the spherical granules in PTST2b silencing lines had a distinctively altered pasting profile, with higher peak and final viscosity than the wild type. Thus, PTST2b and MRC are promising target genes for altering starch granule size and shape in potato tubers, and can be used to create novel starches with altered physicochemical and/or functional properties.</p>","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"23 2","pages":"412-429"},"PeriodicalIF":10.1,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/pbi.14505","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142804520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}