A molecular framework for grain number determination in barley

Huang, Yongyu; Kamal, Roop; Shanmugaraj, Nandhakumar; Rutten, Twan; Thirulogachandar, Venkatasubbu; Zhao, Shuangshuang; Hoffie, Iris; Hensel, Goetz; Rajaraman, Jeyaraman; Moya, Yudelsy Antonia Tandrón; Hajirezaei, Mohammad‐Reza; Himmelbach, Axel; Poursarebani, Naser; Lundqvist, Udda; Kumlehn, Jochen; Stein, Nils; Wirén, Nicolaus von; Mascher, Martin; Melzer, Michael; Schnurbusch, Thorsten

doi:10.1126/sciadv.add0324

Cited by 16 publications

(28 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While GT1 and VRS1 homologs may regulate the number of flowers that develop, additional genetic components may contribute to the maturation of those flowers into seeds. In barley, the CCT MOTIF FAMILY4 (CMF4) gene modulates spikelet survival and maturation through the vascular-associated circadian clock and organ greening (Huang et al, 2023). To maximize the yield-related effect of developing or selecting GT1 and VRS1 homolog alleles that permit more floral development, concurrent selection of floral ←Figure 3: The growth repression role of VRS1 and GT1 homologs is conserved in brachypodium.…”

Section: Discussionmentioning

confidence: 99%

Duplicate transcription factorsGT1andVRS1regulate branching and fertile flower number in maize andBrachypodium distachyon

Gallagher

Man

Chiaramida

et al. 2023

Preprint

View full text Add to dashboard Cite

Crop engineering and de novo domestication using genome editing are new frontiers in agriculture. However, outside of well-studied crops and model systems, prioritizing engineering targets remains challenging. Evolution can serve as our guide, revealing high-priority genes with deeply conserved roles. Indeed,GRASSY TILLERS1(GT1),SIX-ROWED SPIKE1(VRS1), and their homologs have repeatedly been targets of selection in domestication and evolution. This repeated selection may be because these genes have an ancient, conserved role in regulating growth repression. To test this, we determined the roles ofGT1andVRS1homologs in maize (Zea mays) and the distantly related grass brachypodium (Brachypodium distachyon) using CRISPR-Cas9 gene editing and mutant analysis.GT1andVRS1have roles in floral development in maize and barley, respectively. Grass flowers are borne in branching structures called spikelets. In maize spikelets, carpels are suppressed in half of all initiated ear flowers. These spikelets can only produce single grains. We show thatgt1; vrs1-like1(vrl1) mutants have derepressed carpels in ear flowers. Importantly, these plants can produce two grains per spikelet. In brachypodium,bdgt1; bdvrl1mutants have more branches, spikelets, and flowers than wildtype plants, indicating conserved roles forGT1andVRS1homologs in growth suppression. Indeed, maizeGT1can suppress growth inArabidopsis thaliana, separated from the grasses by ca. 160 million years of evolution. Thus,GT1andVRS1maintain their potency as growth regulators across vast timescales and in distinct developmental contexts. Modulating the activity of these and other conserved genes may be critical in crop engineering.

show abstract

Section: Discussionmentioning

confidence: 99%

Duplicate transcription factorsGT1andVRS1regulate branching and fertile flower number in maize andBrachypodium distachyon

Gallagher

Man

Chiaramida

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…These findings suggested that meiotic ability or anther greening at pre‐dimorphism phase was a critical indicator or threshold between fertile or abortive potential of floret primordia. There was an association between anther greening and the ability to become a fertile floret (Huang et al, 2023; Zhang et al, 2021). It is unclear whether the meiotic ability or anther greening was the cause or consequence of floret primordia abortion.…”

Section: Discussionmentioning

confidence: 99%

“…It is unclear whether the meiotic ability or anther greening was the cause or consequence of floret primordia abortion. Previous research revealed that anther greening was dependent on vascular signals and chloroplasts development in the anther (Huang et al, 2023). We rather thought that those floret primordia without meiotic ability or anther greening at pre‐dimorphism phase still did have the capacity to become green and perform meiosis but they were developmentally arrested or inhibited.…”

Section: Discussionmentioning

confidence: 99%

Dynamic gene regulatory networks improving spike fertility through regulation of floret primordia fate in wheat

Zhang

Sun

et al. 2023

Plant Cell & Environment

View full text Add to dashboard Cite

The developmental process of spike is critical for spike fertility through affecting floret primordia fate in wheat; however, the genetic regulation of this dynamic and complex developmental process remains unclear. Here, we conducted a high temporal‐resolution analysis of spike transcriptomes and monitored the number and morphology of floret primordia within spike. The development of all floret primordia in a spike was clearly separated into three distinct phases: differentiation, pre‐dimorphism and dimorphism. Notably, we identified that floret primordia with meiosis ability at the pre‐dimorphism phase usually develop into fertile floret primordia in the next dimorphism phase. Compared to control, increasing plant space treatment achieved the maximum increasement range (i.e., 50%) in number of fertile florets by accelerating spike development. The process of spike fertility improvement was directed by a continuous and dynamic regulatory network involved in transcription factor and genes interaction. This was based on the coordination of genes related to heat shock protein and jasmonic acid biosynthesis during differentiation phase, and genes related to lignin, anthocyanin and chlorophyll biosynthesis during dimorphism phase. The multi‐dimensional association with high temporal‐resolution approach reported here allows rapid identification of genetic resource for future breeding studies to realise the maximum spike fertility potential in more cereal crops.

show abstract

“…To reduce background introgressions from the original mutagenesis recipient (cv. Donaria), we further backcrossed BW883 to wild-type Bowman plants ( Huang et al , 2023 ). The isogenic six-rowed GP -vrs1 line was obtained through targeted mutagenesis conducted by CRISPR-associated (Cas) endonuclease technology ( Thirulogachandar et al , 2024 ).…”

Section: Methodsmentioning

confidence: 99%

“…The influence of spikelet fertility on rachis vasculature was studied in an isogenic six-rowed GP -vrs1 line generated by targeted mutagenesis ( Thirulogachandar et al , 2024 ), and for the effect of a reduction in fertile spikelets, we compared the cv. Bowman with its near-isogenic mutant BW -tst2.b ( Huang et al , 2023 ) exhibiting extended pre-anthesis tip degeneration. Our results confirm the assumption of Waddington et al (1983) that the morphogenesis of the barley rachis vasculature is the result of two distinct processes: initiation and processing, with ultimate vein size being strongly correlated with the number of fertile spikelets.…”

Section: Introductionmentioning

confidence: 99%

Anatomical insights into the vascular layout of the barley rachis: implications for transport and spikelet connection

Rutten,

Thirulogachandar,

Huang

et al. 2024

Annals of Botany

Self Cite

View full text Add to dashboard Cite

Background and aims Vascular patterning is intimately related to plant form and function. Here, using barley (Hordeum vulgare) as a model, we studied the vascular anatomy of the spike-type inflorescence. The main aim of the present work was to clarify the relationship between rachis (spike axis) vasculature and spike size, define vascular dynamics, the implications for transport capacity and its interaction with the spikelets. Methods We employed serial transversal internode sections to determine the internode area, vascular area, and vein number along the rachis of several barley lines. Key results Internode area and total vascular area show a clear positive correlation with spike size, whereas vascular number is only weakly correlated. While the lateral periphery of the rachis contains large mature veins of constant size, the central part is occupied by small immature veins. Spikelet-derived veins entering the rachis often merge with the immature rachis veins but never merge with the mature veins. An increase in floret fertility through the conversion of a two-rowed barley into an isogenic six-rowed line, as well as a decrease in floret fertility due to enhanced pre-anthesis tip degeneration caused by the mutation tip sterile 2.b (tst2.b) significantly affected vein size, but had limited to no effects on vein number or internode area. Conclusions The rachis vasculature is the result of a two-step process involving an initial layoutfollowed by size adjustment according to floret fertility/spike size. The restriction of large mature vessels to the periphery and that of small immature vessels to the center of the rachis suggests that long distance transport and local supply to spikelets are spatially separated processes. The identification of spikelet-derived veins entering the rachis without fusing with its vasculature indicates that a vascular continuity between rachis and spikelets may be non-essential.

show abstract

A molecular framework for grain number determination in barley

Cited by 16 publications

References 83 publications

Duplicate transcription factorsGT1andVRS1regulate branching and fertile flower number in maize andBrachypodium distachyon

Duplicate transcription factorsGT1andVRS1regulate branching and fertile flower number in maize andBrachypodium distachyon

Dynamic gene regulatory networks improving spike fertility through regulation of floret primordia fate in wheat

Anatomical insights into the vascular layout of the barley rachis: implications for transport and spikelet connection

Contact Info

Product

Resources

About