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Chakhao is a popular pigmented black rice variety with remarkably high anthocyanin content. Due to its susceptibility to various biotic and abiotic stresses, its production has remained low. Here, two genes, Pi54 blast-resistant and OsSPL14, high-yielding genes of rice, were pyramided in a Chakhao landrace by crossing with CR Dhan 307. From a total of 147 F4 lines developed, 32 were identified with the positive alleles of both genes, of which 16 were black grain coloured, and their total anthocyanin content ranged from 30.19±2.19 to 240.31±2.62 mg 100 g-1 dried weight. Among these, ChM 68 F4 line had the highest anthocyanin content (240.31 ± 2.62 mg 100 g-1 of powdered grain) with more 118.96 mg 100 g-1 anthocyanin than the recipient parent, CHK13 (121.35±3.32 mg 100 g-1), making it a promising line to be released as a highyielding and durable blast-resistant Chakhao variety in Manipur [ABSTRACT FROM AUTHOR]

The leaf inclination angle is an important agronomic rice trait and an indicator of ideal plant architecture, yield and revenue. Based on 120 recombinant inbred lines (RILs) obtained from crossing of the F1 generation of the indica rice cultivar Huazhan as the male parent and the japonica rice cultivar Nekken2 as the female parent, followed by inbreeding for 12 generations, the leaf inclination angle of the first, second and third leaves from the top of the plants were analyzed. At the same time, quantitative trait locus (QTL) mapping of the leaf inclination angle was performed using encrypted genetic maps constructed for this population. A total of 33 QTLs were detected, including two related to the first leaf inclination angle (FLIA), nine related to the second leaf inclination angle (SLIA) (highest Lod value of 5.94), and 22 related to the third leaf inclination angle (TLIA) (highest Lod value of 8.53). At the same time, candidate genes analysis were conducted on the detected QTLs' intervals, and a total of 15 candidate genes were screened. The expression levels of candidate genes were detected by RT-qPCR, we found that LOC_Os03g46920, LOC_Os03g52630, LOC_Os04g24328, LOC_Os08g25380, LOC_Os09g23200, LOC_Os09g32080, LOC_Os09g35940, LOC_Os09g37330 and LOC_Os09g37495 displayed extremely significant differences in expression between the parents. The results showed that these genes may be the cause of the difference in leaf inclination. The present study provided substantial foundation for the further validation of the function of leaf inclination angle genes and molecular breeding practices. [ABSTRACT FROM AUTHOR]

SUMMARY: Improving crop yield potential through an enhanced response to rising atmospheric CO2 levels is an effective strategy for sustainable crop production in the face of climate change. Large‐sized panicles (containing many spikelets per panicle) have been a recent ideal plant architecture (IPA) for high‐yield rice breeding. However, few breeding programs have proposed an IPA under the projected climate change. Here, we demonstrate through the cloning of the rice (Oryza sativa) quantitative trait locus for MORE PANICLES 3 (MP3) that the improvement in panicle number increases grain yield at elevated atmospheric CO2 levels. MP3 is a natural allele of OsTB1/FC1, previously reported as a negative regulator of tiller bud outgrowth. The temperate japonica allele advanced the developmental process in axillary buds, moderately promoted tillering, and increased the panicle number without negative effects on the panicle size or culm thickness in a high‐yielding indica cultivar with large‐sized panicles. The MP3 allele, containing three exonic polymorphisms, was observed in most accessions in the temperate japonica subgroups but was rarely observed in the indica subgroup. No selective sweep at MP3 in either the temperate japonica or indica subgroups suggested that MP3 has not been involved and utilized in artificial selection during domestication or breeding. A free‐air CO2 enrichment experiment revealed a clear increase of grain yield associated with the temperate japonica allele at elevated atmospheric CO2 levels. Our findings show that the moderately increased panicle number combined with large‐sized panicles using MP3 could be a novel IPA and contribute to an increase in rice production under climate change with rising atmospheric CO2 levels. Significance Statement: Genetic enhancement of crop responses to the rising atmospheric CO2 levels is one way to improve crop productivity under the projected climate change. We demonstrate that a cloned rice (Oryza sativa) quantitative trait locus, MP3, promoted tillering, moderately increased the panicle number without negative effects on the panicle size or culm thickness, and clearly increased the grain yield under elevated atmospheric CO2 conditions, indicating the value for designing a novel high‐yielding ideotype under the projected climate change. [ABSTRACT FROM AUTHOR]

The need to produce crops with higher yields is critical due to a growing global population, depletion of agricultural land, and severe climate change. Compared with the "source" and "sink" transport systems that have been studied a lot, the development and utilization of vascular bundles (conducting vessels in plants) are increasingly important. Due to the complexity of the vascular system, its structure, and its delicate and deep position in the plant body, the current research on model plants remains basic knowledge and has not been repeated for crops and applied to field production. In this review, we aim to summarize the current knowledge regarding biomolecular strategies of vascular bundles in transport systems (source-flow-sink), allocation, helping crop architecture establishment, and influence of the external environment. It is expected to help understand how to use sophisticated and advancing genetic engineering technology to improve the vascular system of crops to increase yield. [ABSTRACT FROM AUTHOR]

Leaf angle (LA) is a key component of maize plant architecture that can simultaneously govern planting density and improve final yield. However, the genetic mechanisms underlying LA have not been fully addressed. To broaden our understanding of its genetic basis, we scored three LA-related traits on upper, middle, and low leaves of 492 maize inbred lines in five environments. Phenotypic data revealed that the three LA-related traits were normally distributed, and significant variation was observed among environments and genotypes. A genome-wide association study (GWAS) was then performed to dissect the genetic factors that control natural variation in maize LA. In total, 85 significant SNPs (involving 32 non-redundant QTLs) were detected (p ≤ 2.04 × 10-6), and individual QTL explained 4.80%-24.09% of the phenotypic variation. Five co-located QTL were detected in at least two environments, and two QTLs were co-located with multiple LA-related traits. Forty-seven meta-QTLs were identified based on meta-analysis combing 294 LA-related QTLs extracted from 18 previously published studies, 816 genes were identified within these meta-QTLs, and seven co-located QTLs were jointly identified by both GWAS and meta-analysis. ZmULA1 was located in one of the co-located QTLs, qLA7, and its haplotypes, hap1 and hap2, differed significantly in LA-related traits. Interestingly, the temperate materials with hap2 had smallest LA. Finally, we also performed haplotype analysis using the reported genes that regulate LA, and identified a lot of maize germplasms that aggregated favorable haplotypes. These results will be helpful for elucidating the genetic basis of LA and breeding new maize varieties with ideal plant architecture. [ABSTRACT FROM AUTHOR]

Achieving ideal plant architecture is of utmost importance for plant improvement to meet the demands of ever-increasing population. The wish list of ideal plant architecture traits varies with respect to its utilization and environmental conditions. Late seed development in woody plants poses difficulties for their propagation, and an increase in regeneration capacity can overcome this problem. The transition of a plant through sequential developmental stages e.g., embryonic, juvenile, and maturity is a well-orchestrated molecular and physiological process. The manipulation in the timing of phase transition to achieve ideal plant traits and regulation of metabolic partitioning will unlock new plant potential. Previous studies demonstrate that micro RNA156 (miR156) impairs the expression of its downstream genes to resist the juvenile-adult-reproductive phase transition to prolonged juvenility. The phenomenon behind prolonged juvenility is the maintenance of stem cell integrity and regeneration is an outcome of re-establishment of the stem cell niche. The previously reported vital and diverse functions of miR156 make it a more important case of study to explore its functions and possible ways to use it in molecular breeding. In this review, we proposed how genetic manipulation of miR156 can be used to reshape plant development phase transition and achieve ideal plant architecture. We have summarized recent studies on miR156 to describe its functional pattern and networking with up and down-stream molecular factors at each stage of the plant developmental life cycle. In addition, we have highlighted unaddressed questions, provided insights and devised molecular pathways that will help researchers to design their future studies. • MicroRNAs are promising tools for orchestrating plant architecture. • Manipulating developmental phase transitions can sustain or enhance desired traits. • MiR156 regulates phase transition, delays aging, and prolongs juvenility. • MiR156-mediated genetic engineering can manipulate phase transition. • MiR156, a phase driver, offers sustainable agriculture, food security, and advancement in plant research. [ABSTRACT FROM AUTHOR]

Bananas (Musa spp.) are an important fruit crop worldwide. The fungus Fusarium oxysporum f. sp. cubense (Foc), which causes Fusarium wilt, is widely regarded as one of the most damaging plant diseases. Fusarium wilt has previously devastated global banana production and continues to do so today. In addition, due to the current use of high-density banana plantations, desirable banana varieties with ideal plant architecture (IPA) possess high lodging resistance, optimum photosynthesis, and efficient water absorption. These properties may help to increase banana production. Genetic engineering is useful for the development of banana varieties with Foc resistance and ideal plant architecture due to the sterility of most cultivars. However, the sustained immune response brought about by genetic engineering is always accompanied by yield reductions. To resolve this problem, we should perform functional genetic studies of the Musa genome, in conjunction with genome editing experiments, to unravel the molecular mechanisms underlying the immune response and the formation of plant architecture in the banana. Further explorations of the genes associated with Foc resistance and ideal architecture might lead to the development of banana varieties with both ideal architecture and pathogen super-resistance. Such varieties will help the banana to remain a staple food worldwide.

Bananas (Musa spp.) are an important fruit crop worldwide. The fungus Fusarium oxysporum f. sp. cubense (Foc), which causes Fusarium wilt, is widely regarded as one of the most damaging plant diseases. Fusarium wilt has previously devastated global banana production and continues to do so today. In addition, due to the current use of high-density banana plantations, desirable banana varieties with ideal plant architecture (IPA) possess high lodging resistance, optimum photosynthesis, and efficient water absorption. These properties may help to increase banana production. Genetic engineering is useful for the development of banana varieties with Foc resistance and ideal plant architecture due to the sterility of most cultivars. However, the sustained immune response brought about by genetic engineering is always accompanied by yield reductions. To resolve this problem, we should perform functional genetic studies of the Musa genome, in conjunction with genome editing experiments, to unravel the molecular mechanisms underlying the immune response and the formation of plant architecture in the banana. Further explorations of the genes associated with Foc resistance and ideal architecture might lead to the development of banana varieties with both ideal architecture and pathogen super-resistance. Such varieties will help the banana to remain a staple food worldwide. [ABSTRACT FROM AUTHOR]

Crop domestication and breeding considerably increased productivity over centuries but unconsciously lowered 'selfish plant behavior' or individual plant fitness. Paradoxically, enhancing individual plant fitness is mistakenly equated with crop improvement. Because agriculture relies on community performance, embracing an agroecological genetics and genomics viewpoint might maximize communal yield by matching crop genotypes to target environments. [ABSTRACT FROM AUTHOR]

High-stress resistance and yield are major goals in crop cultivation, which can be addressed by modifying plant architecture. Significant progress has been made in recent years to understand how plant architecture is controlled under various growth conditions, recognizing the central role phytohormones play in response to environmental stresses. miRNAs, transcription factors, and other associated proteins regulate plant architecture, mainly via the modulation of hormone homeostasis and signaling. To generate crop plants of ideal architecture, we propose simultaneous editing of multiple genes involved in the regulatory networks associated with plant architecture as a feasible strategy. This strategy can help to address the need to increase grain yield and/or stress resistance under the pressures of the ever-increasing world population and climate change. Plant hormone homeostasis modulates plant architecture, crop yield, and resistance to environmental stresses. miRNAs, phytohormones, key transcription factors, and other important signaling proteins form complex networks to regulate plant hormone homeostasis. Some transcription factors act as system integrators of internal and external signals to regulate lateral organ angles and/or orientations and/or branch and tiller numbers. Modification of plant architecture by fine-tuning the expression of key genes has proved to be a promising strategy to improve yield and/or stress resistance. [ABSTRACT FROM AUTHOR]

Rice is one of the most consumed crops worldwide and the genetic and molecular basis of its grain yield attributes are well understood. Various studies have identified different yield-related parameters in rice that are regulated by the microRNAs (miRNAs). MiRNAs are endogenous small non-coding RNAs that silence gene expression during or after transcription. They control a variety of biological or genetic activities in plants including growth, development and response to stress. In this review, we have summarized the available information on the genetic control of panicle architecture and grain yield (number and morphology) in rice. The miRNA nodes that are associated with their regulation are also described while focussing on the central role of miR156- SPL node to highlight the co-regulation of two master regulators that determine the fate of panicle development. Since abiotic stresses are known to negatively affect yield, the impact of abiotic stress induced alterations on the levels of these miRNAs are also discussed to highlight the potential of miRNAs for regulating crop yields. • This review contains all available information on the genetic control of panicle architecture and grain yield (number and morphology) in rice. • The miRNA nodes that are associated with this process are described • The impact of abiotic stress induced alterations on the levels of the miRNAs related to grain yield is discussed. • The role of miR156- SPL node has been discussed in details. [ABSTRACT FROM AUTHOR]

The majority of investigations on mechanisms underlying yield difference between superior and conventional cultivars has focused on the grain-filling stage after anthesis. However, the physiological process before anthesis has been less explored. We aimed to quantify the contribution of canopy photosynthesis at pre-anthesis stage to grain yield formation and clarify the mechanism underlying the yield advantage of the superior cultivars. This study selected representative cultivars of indica and japonica rice, each type having a pair of cultivars with ideal plant architecture (IPA) and conventional architecture. Field experiments over four years (2019–2022) were conducted to compare the relevance of canopy photosynthesis to yield formation between the phases before and after anthesis. The two IPA cultivars, JYZK-6 and ZZY-1, produced higher grain yield than the two conventional cultivars, NJ-5055 and HHZ. JYZK-6 and ZZY-1 also had good distribution of light interception inside the canopy, with the middle and lower part receiving more light than NJ-5055 and HHZ. At leaf level, there was no significant difference in photosynthetic rate between the two types of cultivars. At canopy level, the IPA cultivars had stronger photosynthetic activities before anthesis, outperforming NJ-5055 by 35.56% in averaged canopy photosynthesis, and by 46.65% in averaged daily net photosynthetic accumulation in 2021–2022. By contrast, canopy photosynthesis after anthesis was not significantly different between the two types. The IPA cultivars stored heavier biomass in internodes and sheaths before anthesis and remobilized more reserves to the developing grains, with the remobilization rate being 16.42% (internodes) and 35.34% (sheaths) higher than NJ-5055 and HHZ. The higher canopy productivity before anthesis is one of the main reasons accounting for the superior IPA cultivars, suggesting the necessity of optimizing plant growth and development during the vegetative and reproductive phases. • Canopy photosynthesis was compared between IPA and conventional cultivars. • IPA cultivars had a good distribution of light interception inside the canopy. • IPA cultivars had stronger canopy photosynthetic activities before anthesis. • We suggest the necessity of optimizing canopy structure development before anthesis. [ABSTRACT FROM AUTHOR]

Plants exhibit phenotypical plasticity. Their general body plan is genetically determined, but plant architecture and branching patterns are variable and can be adjusted to the prevailing environmental conditions. The modular design of the plant facilitates such morphological adaptations. The prerequisite for the formation of a branch is the initiation of an axillary meristem. Here, we review the current knowledge about this process. After its establishment, the meristem can develop into a bud which can either become dormant or grow out and form a branch. Many endogenous factors, such as photoassimilate availability, and exogenous factors like nutrient availability or shading, have to be integrated in the decision whether a branch is formed. The underlying regulatory network is complex and involves phytohormones and transcription factors. The hormone auxin is derived from the shoot apex and inhibits bud outgrowth indirectly in a process termed apical dominance. Strigolactones appear to modulate apical dominance by modification of auxin fluxes. Furthermore, the transcription factor BRANCHED1 plays a central role. The exact interplay of all these factors still remains obscure and there are alternative models. We discuss recent findings in the field along with the major models. Plant architecture is economically significant because it affects important traits of crop and ornamental plants, as well as trees cultivated in forestry or on short rotation coppices. As a consequence, plant architecture has been modified during plant domestication. Research revealed that only few key genes have been the target of selection during plant domestication and in breeding programs. Here, we discuss such findings on the basis of various examples. Architectural ideotypes that provide advantages for crop plant management and yield are described. We also outline the potential of breeding and biotechnological approaches to further modify and improve plant architecture for economic needs. [ABSTRACT FROM AUTHOR]