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<jats:title>SUMMARY</jats:title><jats:p>Hybrid breeding is a promising strategy to quickly improve wheat yield and stability. Due to the usefulness of the <jats:italic>Rht</jats:italic> ‘Green Revolution’ dwarfing alleles, it is important to gain a better understanding of their impact on traits related to hybrid development. Traits associated with cross‐pollination efficiency were studied using Near Isogenic Lines carrying the different sets of alleles in <jats:italic>Rht</jats:italic> genes: <jats:italic>Rht1</jats:italic> (semi‐dwarf), <jats:italic>Rht2</jats:italic> (semi‐dwarf), <jats:italic>Rht1 + 2</jats:italic> (dwarf), <jats:italic>Rht3</jats:italic> (extreme dwarf), <jats:italic>Rht2 + 3</jats:italic> (extreme dwarf), and <jats:italic>rht</jats:italic> (tall) during four growing seasons. Results showed that the extreme dwarfing alleles <jats:italic>Rht2 + 3</jats:italic>, <jats:italic>Rht3</jats:italic>, and <jats:italic>Rht1 + 2</jats:italic> presented the greatest effects in all the traits analyzed. Plant height showed reductions up to 64% (<jats:italic>Rht2 + 3</jats:italic>) compared to <jats:italic>rht</jats:italic>. Decreases up to 20.2% in anther length and 33% in filament length (<jats:italic>Rht2 + 3</jats:italic>) were observed. Anthers extrusion decreased from 40% (<jats:italic>rht</jats:italic>) to 20% (<jats:italic>Rht1</jats:italic> and <jats:italic>Rht2</jats:italic>), 11% (<jats:italic>Rht3</jats:italic>), 8.3% (<jats:italic>Rht1 + 2</jats:italic>), and 6.5% (<jats:italic>Rht2 + 3</jats:italic>). Positive correlations were detected between plant height and anther extrusion, anther, and anther filament lengths, suggesting the negative effect of dwarfing alleles. Moreover, the magnitude of these negative impacts depends on the combination of the alleles: <jats:italic>Rht2 + 3</jats:italic> &gt; <jats:italic>Rht3</jats:italic>/<jats:italic>Rht1 + 2</jats:italic> &gt; <jats:italic>Rht2</jats:italic>/<jats:italic>Rht1</jats:italic> &gt; <jats:italic>rht</jats:italic> (tall). Reductions were consistent across genotypes and environments with interactions due to magnitude effects. Our results indicate that <jats:italic>Rht</jats:italic> alleles are involved in multiple traits of interest for hybrid wheat production and the need to select alternative sources for reduced height/lodging resistance for hybrid breeding programs.</jats:p>

<jats:title>SUMMARY</jats:title><jats:p>The sugarcane (<jats:italic>Saccharum</jats:italic> spp.) genome is one of the most complex of all. Modern varieties are highly polyploid and aneuploid as a result of hybridization between <jats:italic>Saccharum officinarum</jats:italic> and <jats:italic>S. spontaneum</jats:italic>. Little research has been done on meiotic control in polyploid species, with the exception of the wheat <jats:italic>Ph1</jats:italic> locus harboring the <jats:italic>ZIP4</jats:italic> gene (<jats:italic>TaZIP4</jats:italic>‐B2) which promotes pairing between homologous chromosomes while suppressing crossover between homeologs. In sugarcane, despite its interspecific origin, bivalent association is favored, and multivalents, if any, are resolved at the end of prophase I. Thus, our aim herein was to investigate the purported genetic control of meiosis in the parental species and in sugarcane itself. We investigated the <jats:italic>ZIP4</jats:italic> gene and immunolocalized meiotic proteins, namely synaptonemal complex proteins Zyp1 and Asy1. The sugarcane <jats:italic>ZIP4</jats:italic> gene is located on chromosome 2 and expressed more abundantly in flowers, a similar profile to that found for <jats:italic>TaZIP4</jats:italic>‐B2. <jats:italic>ZIP4</jats:italic> expression is higher in <jats:italic>S. spontaneum</jats:italic> a neoautopolyploid, with lower expression in <jats:italic>S. officinarum</jats:italic>, a stable octoploid species. The sugarcane Zip4 protein contains a TPR domain, essential for scaffolding. Its 3D structure was also predicted, and it was found to be very similar to that of <jats:italic>TaZIP4</jats:italic>‐B2, reflecting their functional relatedness. Immunolocalization of the Asy1 and Zyp1 proteins revealed that <jats:italic>S. officinarum</jats:italic> completes synapsis. However, in <jats:italic>S. spontaneum</jats:italic> and SP80‐3280 (a modern variety), no nuclei with complete synapsis were observed. Importantly, our results have implications for sugarcane cytogenetics, genetic mapping, and genomics.</jats:p>

<jats:title>SUMMARY</jats:title><jats:p>With global climate change, the high‐temperature environment has severely impacted the community structure and phenotype of marine diatoms. <jats:italic>Phaeodactylum tricornutum</jats:italic>, a model species of marine diatom, is sensitive to high temperature, which grow slowly under high temperature. However, the regulatory mechanism of <jats:italic>P. tricornutum</jats:italic> in response to high‐temperature is still unclear. In this study, we found that the expression level of the <jats:italic>HSP70A</jats:italic> in the wild type (WT) increased 28 times when exposed to high temperature (26°C) for 1 h, indicating that HSP70A plays a role in high temperature in <jats:italic>P. tricornutum</jats:italic>. Furthermore, overexpression and interference of <jats:italic>HSP70A</jats:italic> have great impact on the exponential growth phase of <jats:italic>P. tricornutum</jats:italic> under 26°C. Moreover, the results of Co‐immunoprecipitation (Co‐IP) suggested that HSP70A potentially involved in the correct folding of the photosynthetic system‐related proteins (D1/D2), preventing aggregation. The photosynthetic activity results demonstrated that overexpression of <jats:italic>HSP70A</jats:italic> improves non‐photochemical quenching (NPQ) activity under high‐temperature stress. These results reveal that HSP70A regulates the photosynthetic activity of <jats:italic>P. tricornutum</jats:italic> under high temperatures. This study not only helps us to understand the photosynthetic activity of marine diatoms to high temperature but also provides a molecular mechanism for HSP70A in <jats:italic>P. tricornutum</jats:italic> under high‐temperature stress.</jats:p>

<jats:title>SUMMARY</jats:title><jats:p>Photoperiod insensitivity (auto‐flowering) in drug‐type <jats:italic>Cannabis sativa</jats:italic> circumvents the need for short day (SD) flowering requirements making outdoor cultivation in high latitudes possible. However, the benefits of photoperiod insensitivity are counterbalanced by low cannabinoid content and poor flower quality in auto‐flowering genotypes. Despite recent studies in cannabis flowering, a mechanistic understanding of photoperiod insensitivity is still lacking. We used a combination of genome‐wide association study and genetic fine‐mapping to identify the genetic cause of auto‐flowering in cannabis. We then used gene expression analyses and transient transformation assays to characterize flowering time control. Herein, we identify a splice site mutation within circadian clock gene <jats:italic>PSEUDO‐RESPONSE REGULATOR 37</jats:italic> (<jats:italic>CsPRR37</jats:italic>) in auto‐flowering cannabis. We show that CsPRR37 represses <jats:italic>FT</jats:italic> expression and its circadian oscillations transition to a less repressive state during SD as compared to long days (LD). We identify several key circadian clock genes whose expression is altered in auto‐flowering cannabis, particularly under non‐inductive LD. Research into the pervasiveness of this mutation and others affecting flowering time will help elucidate cannabis domestication history and advance cannabis breeding toward a more sustainable outdoor cultivation system.</jats:p>

<jats:title>SUMMARY</jats:title><jats:p>Rice (<jats:italic>Oryza sativa</jats:italic> L.) is a short‐day plant whose heading date is largely determined by photoperiod sensitivity (PS). Many parental lines used in hybrid rice breeding have weak PS, but their F<jats:sub>1</jats:sub> progenies have strong PS and exhibit an undesirable transgressive late‐maturing phenotype. However, the genetic basis for this phenomenon is unclear. Therefore, effective methods are needed for selecting parents to create F<jats:sub>1</jats:sub> hybrid varieties with the desired PS. In this study, we used bulked segregant analysis with F<jats:sub>1</jats:sub> Ningyou 1179 (strong PS) and its F<jats:sub>2</jats:sub> population, and through analyzing both parental haplotypes and PS data for 918 hybrid rice varieties, to identify the genetic basis of transgressive late maturation which is dependent on dominance complementation effects of <jats:italic>Hd1</jats:italic>, <jats:italic>Ghd7</jats:italic>, <jats:italic>DTH8</jats:italic>, and <jats:italic>PRR37</jats:italic> from both parents rather than from a single parental genotype. We designed a molecular marker‐assisted selection system to identify the genotypes of <jats:italic>Hd1</jats:italic>, <jats:italic>Ghd7</jats:italic>, <jats:italic>DTH8</jats:italic>, and <jats:italic>PRR37</jats:italic> in parental lines to predict PS in F<jats:sub>1</jats:sub> plants prior to crossing. Furthermore, we used CRISPR/Cas9 technique to knock out <jats:italic>Hd1</jats:italic> in Ning A (sterile line) and Ning B (maintainer line) and obtained an <jats:italic>hd1</jats:italic>‐NY material with weak PS while retaining the elite agronomic traits of NY. Our findings clarified the genetic basis of transgressive late maturation in hybrid rice and developed effective methods for parental selection and gene editing to facilitate the breeding of hybrid varieties with the desired PS for improving their adaptability.</jats:p>

<jats:title>SUMMARY</jats:title><jats:p>Plant height (PH) is an important factor affecting bast fiber yield in jute. Here, we report the mechanism of dwarfism in the ‘<jats:italic>Guangbaai</jats:italic>’ (<jats:italic>gba</jats:italic>) of jute. The mutant <jats:italic>gba</jats:italic> had shorter internode length and cell length compared to the standard cultivar ‘TaiZi 4’ (TZ4). Exogenous GA<jats:sub>3</jats:sub> treatment indicated that <jats:italic>gba</jats:italic> is a GA‐insensitive dwarf mutant. Quantitative trait locus (QTL) analysis of three PH‐related traits via a high‐density genetic linkage map according to re‐seq showed that a total of 25 QTLs were identified, including 13 QTLs for PH, with phenotypic variation explained ranging from 2.42 to 74.16%. Notably, the functional mechanism of the candidate gene <jats:italic>CoGID1a</jats:italic>, the gibberellic acid receptor, of the major locus <jats:italic>qPHIL5</jats:italic> was evaluated by transgenic analysis and virus‐induced gene silencing. A dwarf phenotype‐related single nucleotide mutation in <jats:italic>CoGID1a</jats:italic> was identified in <jats:italic>gba</jats:italic>, which was also unique to the dwarf phenotype of <jats:italic>gba</jats:italic> among 57 cultivars. <jats:italic>Cogid1a</jats:italic> was unable to interact with the growth‐repressor DELLA even in the presence of highly accumulated gibberellins in <jats:italic>gba</jats:italic>. Differentially expressed genes between transcriptomes of <jats:italic>gba</jats:italic> and TZ4 after GA<jats:sub>3</jats:sub> treatment indicated up‐regulation of genes involved in gibberellin and cellulose synthesis in <jats:italic>gba</jats:italic>. Interestingly, it was found that up‐regulation of <jats:italic>CoMYB46</jats:italic>, a key transcription factor in the secondary cell wall, by the highly accumulated gibberellins in <jats:italic>gba</jats:italic> promoted the expression of cellulose synthase genes <jats:italic>CoCesA4</jats:italic> and <jats:italic>CoCesA7</jats:italic>. These findings provide valuable insights into fiber development affected by endogenous gibberellin accumulation in plants.</jats:p>

<jats:title>SUMMARY</jats:title><jats:p>The basal region of maize (<jats:italic>Zea mays</jats:italic>) kernels, which includes the pedicel, placenta‐chalazal, and basal endosperm transfer layers, serves as the maternal/filial interface for nutrient transfer from the mother plant to the developing seed. However, transcriptome dynamics of this maternal/filial interface remain largely unexplored. To address this gap, we conducted high‐temporal‐resolution RNA sequencing of the basal and upper kernel regions between 4 and 32 days after pollination and deeply analyzed transcriptome dynamics of the maternal/filial interface. Utilizing 790 specifically and highly expressed genes in the basal region, we performed the gene ontology (GO) term and weighted gene co‐expression network analyses. In the early‐stage basal region, we identified five MADS‐box transcription factors (TFs) as hubs. Their homologs have been demonstrated as pivotal regulators at the maternal/filial interface of rice or Arabidopsis, suggesting their potential roles in maize kernel development. In the filling‐stage basal region, numerous GO terms associated with transcriptional regulation and transporters are significantly enriched. Furthermore, we investigated the molecular function of three hub TFs. Through genome‐wide DNA affinity purification sequencing combined with promoter transactivation assays, we suggested that these three TFs act as regulators of 10 basal‐specific transporter genes involved in the transfer of sugars, amino acids, and ions. This study provides insights into transcriptomic dynamic and regulatory modules of the maternal/filial interface. In the future, genetic investigation of these hub regulators must advance our understanding of maternal/filial interface development and function.</jats:p>

<jats:title>SUMMARY</jats:title><jats:p>As a major worldwide root crop, the mechanism underlying storage root yield formation has always been a hot topic in sweet potato [<jats:italic>Ipomoea batatas</jats:italic> (L.) Lam.]. Previously, we conducted the transcriptome database of differentially expressed genes between the cultivated sweet potato cultivar “Xushu18,” its diploid wild relative <jats:italic>Ipomoea triloba</jats:italic> without storage root, and their interspecific somatic hybrid XT1 with medium‐sized storage root. We selected one of these candidate genes, <jats:italic>IbNF‐YA1</jats:italic>, for subsequent analysis. <jats:italic>IbNF‐YA1</jats:italic> encodes a nuclear transcription factor Y subunit alpha (NF‐YA) gene, which is significantly induced by the natural auxin indole‐3‐acetic acid (IAA). The storage root yield of the <jats:italic>IbNF‐YA1</jats:italic> overexpression (OE) plant decreased by 29.15–40.22% compared with the wild type, while that of the RNAi plant increased by 10.16–21.58%. Additionally, IAA content increased significantly in OE plants. Conversely, the content of IAA decreased significantly in RNAi plants. Furthermore, real‐time quantitative reverse transcription‐PCR (qRT‐PCR) analysis demonstrated that the expressions of the key genes <jats:italic>IbYUCCA2</jats:italic>, <jats:italic>IbYUCCA4</jats:italic>, and <jats:italic>IbYUCCA8</jats:italic> in the IAA biosynthetic pathway were significantly changed in transgenic plants. The results indicated that IbNF‐YA1 could directly target <jats:italic>IbYUCCA4</jats:italic> and activate <jats:italic>IbYUCCA4</jats:italic> transcription. The IAA content of <jats:italic>IbYUCCA4</jats:italic> OE plants increased by 71.77–98.31%. Correspondingly, the storage root yield of the <jats:italic>IbYUCCA4</jats:italic> OE plant decreased by 77.91–80.52%. These findings indicate that downregulating the <jats:italic>IbNF‐YA1</jats:italic> gene could improve the storage root yield in sweet potato.</jats:p>