Planta最新文献

Main conclusion: In the early diverging angiosperm Trithuria submersa TsAG1 and TsAG2 are expressed in different flower organs, including bracts, while TsAG3 is more ovule-specific, probably functioning as a D-type gene. Species of Trithuria, the only genus of the family Hydatellaceae, represent ideal candidates to explore the biology and flower evolution of early diverging angiosperms. The life cycle of T. submersa is generally known, and the "reproductive units" are morphologically well described, but the availability of genetic and developmental data of T. submersa is still scarce. To fill this gap, a transcriptome analysis of the reproductive structures was performed and presented in this work. This analysis provided sequences of MADS-box transcription factors, a gene family known to be involved in flower and fruit development. In situ hybridization experiments on floral buds were performed to describe the spatiotemporal expression patterns of the AGAMOUS genes, revealing the existence of three AG genes with different expression domains in flower organs and in developing ovules. Trithuria may offer important clues to the evolution of reproductive function among early angiosperms and Nymphaeales in particular, and this study aims to broaden relevant knowledge regarding key genes of reproductive development in non-model angiosperms, shaping first flower appearance and evolution.

Main conclusion: Plants lacking shoot apical meristem develop with unique body shapes, suggesting rewiring of developmental genes. This loss of the meristem is likely influenced by a combination of environmental factors and evolutionary pressures. This study explores the development of plant bodies in three families (Podostemaceae, Lemnaceae, and Gesneriaceae) where the shoot apical meristem (SAM), a key structure for growth, is absent or altered. The review highlights alternative developmental strategies these plants employ. Also, we considered alternative reproduction in those species, namely through structures like turions, fronds, or modified leaves, bypassing the need for a SAM. Further, we report on studies based on the expression patterns of genes known to be involved in SAM formation and function. Interestingly, these genes are still present but expressed in atypical locations, suggesting a rewiring of developmental networks. Our view on the current literature and knowledge indicates that the loss or reduction of the SAM is driven by a combination of environmental pressures and evolutionary constraints, leading to these unique morphologies. Further research, also building on Next-Generation Sequencing, will be instrumental to explore the genetic basis for these adaptations and how environmental factors influence them.

Main conclusion: Leveraging advanced breeding and multi-omics resources is vital to position millet as an essential "nutricereal resource," aligning with IYoM goals, alleviating strain on global cereal production, boosting resilience to climate change, and advancing sustainable crop improvement and biodiversity. The global challenges of food security, nutrition, climate change, and agrarian sustainability demand the adoption of climate-resilient, nutrient-rich crops to support a growing population amidst shifting environmental conditions. Millets, also referred to as "Shree Anna," emerge as a promising solution to address these issues by bolstering food production, improving nutrient security, and fostering biodiversity conservation. Their resilience to harsh environments, nutritional density, cultural significance, and potential to enhance dietary quality index made them valuable assets in global agriculture. Recognizing their pivotal role, the United Nations designated 2023 as the "International Year of Millets (IYoM 2023)," emphasizing their contribution to climate-resilient agriculture and nutritional enhancement. Scientific progress has invigorated efforts to enhance millet production through genetic and genomic interventions, yielding a wealth of advanced molecular breeding technologies and multi-omics resources. These advancements offer opportunities to tackle prevailing challenges in millet, such as anti-nutritional factors, sensory acceptability issues, toxin contamination, and ancillary crop improvements. This review provides a comprehensive overview of molecular breeding and multi-omics resources for nine major millet species, focusing on their potential impact within the framework of IYoM. These resources include whole and pan-genome, elucidating adaptive responses to abiotic stressors, organelle-based studies revealing evolutionary resilience, markers linked to desirable traits for efficient breeding, QTL analysis facilitating trait selection, functional gene discovery for biotechnological interventions, regulatory ncRNAs for trait modulation, web-based platforms for stakeholder communication, tissue culture techniques for genetic modification, and integrated omics approaches enabled by precise application of CRISPR/Cas9 technology. Aligning these resources with the seven thematic areas outlined by IYoM catalyzes transformative changes in millet production and utilization, thereby contributing to global food security, sustainable agriculture, and enhanced nutritional consequences.

Main conclusion: Millets are important food source to ensure global food and nutritional security and are associated with health benefits. Millets have emerged as a nutritional powerhouse with the potential to address food security challenges worldwide. These ancient grains, which come in various forms, including finger millet, proso millet, and pearl millet, among others, are essential to a balanced diet, since they provide a wide range of nutritional advantages. Millets have a well-rounded nutritional profile with a high protein, dietary fiber, vitamin, and mineral content for optimal health and wellness. In addition to their nutritional advantages, millets exhibit remarkable adaptability and durability to various agroecological conditions, making them a valuable resource for smallholder farmers functioning in resource-poor regions. Promoting the growth and use of millet can lead to several benefits that researchers and development experts may discover, including improved nutrition, increased food security, and sustainable agricultural methods. Therefore, millets are food crops, that are climate smart, nutritional, and food secured to feed the increasing global population, and everyone could have a healthier, more resilient future.

Main conclusion: A comprehensive understanding of the nucleocytoplasmic interactions that occur between genes related to the restoration of fertility and cytoplasmic male sterility (CMS) provides insight into the development of hybrids of important crop species. Modern biotechnological techniques allow this to be achieved in an efficient and quick manner. Heterosis is paramount for increasing the yield and quality of a crop. The development of hybrids for achieving heterosis has been well-studied and proven to be robust and efficient. Cytoplasmic male sterility (CMS) has been explored extensively in the production of hybrids. The underlying mechanisms of CMS include the role of cytotoxic proteins, PCD of tapetal cells, and improper RNA editing of restoration factors. On the other hand, the restoration of fertility is caused by the presence of restorer-of-fertility (Rf) genes or restorer genes, which inhibit the effects of sterility-causing genes. The interaction between mitochondria and the nuclear genome is crucial for several regulatory pathways, as observed in the CMS-Rf system and occurs at the genomic, transcriptional, post-transcriptional, translational, and post-translational levels. These CMS-Rf mechanisms have been validated in several crop systems. This review aims to summarize the nucleo-mitochondrial interaction mechanism of the CMS-Rf system. It also sheds light on biotechnological interventions, such as genetic engineering and genome editing, to achieve CMS-based hybrids.

Main conclusion: The leaf color asymmetry found in the reciprocal hybrids C. hystrix × C. sativus (HC) and C. sativus × C. hystrix (CH) could be influenced by the CsPPR gene (CsaV3_1G038250.1). Most angiosperm organelles are maternally inherited; thus, the reciprocal hybrids usually exhibit asymmetric phenotypes that are associated with the maternal parent. However, there are two sets of organelle genomes in the plant cytoplasm, and the mechanism of reciprocal differences are more complex and largely unknown, because the chloroplast genes are involved besides mitochondrial genes. Cucumis spp. contains the species, i.e., cucumber and melon, which chloroplasts and mitochondria are maternally inherited and paternally inherited, respectively, serving as good materials for the study of reciprocal differences. In this study, leaf color asymmetry was observed in the reciprocal hybrids (HC and CH) derived from C. sativus (2n = 14, CC) and C. hystrix (2n = 24, HH), where the leaves of HC were found to have reduced chlorophyll content, abnormal chloroplast structure and lower photosynthetic capacity. Transcriptomic analysis revealed that the chloroplast development-related genes were differentially expressed in leaf color asymmetry. Genetic analysis showed that leaf color asymmetry was caused by the maternal chloroplast genome. Comparative analysis of chloroplast genomes revealed that there was no mutation in the chloroplast genome during interspecific hybridization. Moreover, a PPR gene (CsaV3_1G038250.1) with RNA-editing function was found to be involved in the regulation of leaf color asymmetry. These findings provide new insights into the regulatory mechanisms of asymmetric phenotypes in plant reciprocal crosses.

Main conclusion

The review article summarizes the approaches and potential targets to address the challenges of anti-nutrient like phytic acid in millet grains for nutritional improvement.

Abstract

Millets are a diverse group of minor cereal grains that are agriculturally important, nutritionally rich, and the oldest cereals in the human diet. The grains are important for protein, vitamins, macro and micronutrients, fibre, and energy sources. Despite a high amount of nutrients, millet grains also contain anti-nutrients that limit the proper utilization of nutrients and finally affect their dietary quality. Our study aims to outline the genomic information to identify the target areas of research for the exploration of candidate genes for nutritional importance and show the possibilities to address the presence of anti-nutrient (phytic acid) in millets. So, the physicochemical accessibility of micronutrients increases and the agronomic traits can do better. Several strategies have been adopted to minimize the phytic acid, a predominant anti-nutrient in cereal grains. In the present review, we highlight the potential of biotechnological tools and genome editing approaches to address phytic acid in millets. It also highlights the biosynthetic pathway of phytic acid and potential targets for knockout or silencing to achieve low phytic acid content in millets.

Main conclusion

The key genetic variation underlying the evo-devo of ICS in Solanaceae may be further pinpointed using an integrated strategy of forward and reverse genetics studies under the framework of phylogeny.

Abstract

The calyx of Physalis remains persistent throughout fruit development. Post-flowering, the fruiting calyx is inflated rapidly to encapsulate the berry, giving rise to a “Chinese lantern” structure called inflated calyx syndrome (ICS). It is unclear how this novelty arises. Over the past 2 decades, the role of MADS-box genes in the evolutionary development (evo-devo) of ICS has mainly been investigated within Solanaceae. In this review, we analyze the main achievements, challenges, and new progress. ICS acts as a source for fruit development, provides a microenvironment to protect fruit development, and assists in long-distance fruit dispersal. ICS is a typical post-floral trait, and the onset of its development is triggered by specific developmental signals that coincide with fertilization. These signals can be replaced by exogenous gibberellin and cytokinin application. MPF2-like heterotopic expression and MBP21-like loss have been proposed to be two essential evolutionary events for ICS origin, and manipulating the related MADS-box genes has been shown to affect the ICS size, sepal organ identity, and/or male fertility, but not completely disrupt ICS. Therefore, the core genes or key links in the ICS biosynthesis pathways may have undergone secondary mutations during evolution, or they have not yet been pinpointed. Recently, we have made some encouraging progress in acquiring lantern mutants in Physalis floridana. In addition to technological innovation, we propose an integrated strategy to further analyze the evo-devo mechanisms of ICS in Solanaceae using forward and reverse genetics studies under the framework of phylogeny.

Main Conclusion

Microscopic analyses and chemical profiling demonstrate that the white rind phenotype in melon fruit is associated with the accumulation of n-alkanes, fatty alcohols, aldehydes and wax esters.

Abstract

Serving as an indicator of quality, the rind (or external) color of fruit directly affects consumer choice. A fruit’s color is influenced by factors such as the levels of pigments and deposited epicuticular waxes. The latter produces a white-grayish coating often referred to as “wax bloom”. Previous reports have suggested that some melon (Cucumis melo L.) accessions may produce wax blooms, where a dominant white rind color trait was genetically mapped to a major locus on chromosome 7 and suggested to be inherited as a single gene named Wi. We here provide the first direct evidence of the contribution of epicuticular waxes to the dominant white rind trait in melon fruit. Our light and electron microscopy and gas chromatography-mass spectrometry (GC–MS) comparative analysis of melon accessions with white or green rinds reveals that the rind of melon fruit is rich in epicuticular waxes. These waxes are composed of various biochemical classes, including fatty acids, fatty alcohols, aldehydes, fatty amides, n-alkanes, tocopherols, triterpenoids, and wax esters. We show that the dominant white rind phenotype in melon fruit is associated with increased accumulation of n-alkanes, fatty alcohols, aldehydes and wax esters, which are linked with the deposition of crystal-like wax platelets on their surfaces. Together, this study broadens the understanding of natural variation in an important quality trait of melon fruit and promotes the future identification of the causative gene for the dominant white rind trait.

Graphical abstract

Main conclusion

Four cultivars of Paeonia lactiflora pollen have a different viability after cryopreservation, and that the difference of pollen viability is related to calcium ions and cell wall deposition.

Abstract

Cryopreservation is a vital technique for preserving germplasm resources, offering extensive application prospects. Understanding the factors influencing pollen viability after cryopreservation is crucial for the permanent preservation and exchange of pollen resources. This study investigated pollen from four Paeonia lactiflora cultivars with varying viability after cryopreservation, aiming to determine whether calcium ions (Ca²⁺) and cell wall deposition affect these viability changes. The results showed that Ca²⁺-ATPase activity and cytoplasmic Ca²⁺ of all four cultivars exhibited an increasing trend after cryopreservation; the calmodulin (CaM) content varied with cultivars. Correlation analysis showed that fresh pollen viability was significantly negatively correlated with cytoplasmic Ca²⁺ content and positively correlated with Ca²⁺-ATPase activity, while pollen viability after cryopreservation exhibited a significantly negative correlation with cytoplasmic Ca²⁺ content and a positive correlation with CaM content. The pollen cell wall of the cultivar ‘Zi Feng Chao Yang’ (ZFCY), which showed increased viability after cryopreservation, contained significantly higher levels of low-temperature tolerance-related phospholipids and proteins compared to other cultivars. Additionally, all cultivars maintained a clear Ca²⁺ gradient at the tips of pollen tubes after cryopreservation, without significant callose accumulation. These findings suggest that differences in Ca²⁺ signaling and cell wall components deposition influence changes in pollen viability after cryopreservation, and the Ca²⁺ gradient and callose at the tip of pollen tubes are not responsible for preventing pollen tube growth.