Fertility of Pedicellate Spikelets in Sorghum Is Controlled by a Jasmonic Acid Regulatory Module

As in other cereal crops, the panicles of sorghum (Sorghum bicolor (L.) Moench) comprise two types of floral spikelets (grass flowers). Only sessile spikelets (SSs) are capable of producing viable grains, whereas pedicellate spikelets (PSs) cease development after initiation and eventually abort. Consequently, grain number per panicle (GNP) is lower than the total number of flowers produced per panicle. The mechanism underlying this differential fertility is not well understood. To investigate this issue, we isolated a series of ethyl methane sulfonate (EMS)-induced multiseeded (msd) mutants that result in full spikelet fertility, effectively doubling GNP. Previously, we showed that MSD1 is a TCP (Teosinte branched/Cycloidea/PCF) transcription factor that regulates jasmonic acid (JA) biosynthesis, and ultimately floral sex organ development. Here, we show that MSD2 encodes a lipoxygenase (LOX) that catalyzes the first committed step of JA biosynthesis. Further, we demonstrate that MSD1 binds to the promoters of MSD2 and other JA pathway genes. Together, these results show that a JA-induced module regulates sorghum panicle development and spikelet fertility. The findings advance our understanding of inflorescence development and could lead to new strategies for increasing GNP and grain yield in sorghum and other cereal crops.

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Fertility of Pedicellate Spikelets in Sorghum is Controlled by a Jasmonic Acid Regulatory Module

10.1101/773564 ◽

2019 ◽

Author(s):

Nicholas Gladman ◽

Yinping Jiao ◽

Young Koung Lee ◽

Lifang Zhang ◽

Ratan Chopra ◽

...

Keyword(s):

Transcription Factor ◽

Jasmonic Acid ◽

Sorghum Bicolor ◽

Spikelet Fertility ◽

Cereal Crops ◽

Grain Number ◽

Regulatory Module ◽

Induced Module ◽

Acid Pathway ◽

Floral Meristems

AbstractAs in other cereal crops, the panicles of sorghum (Sorghum bicolor (L.) Moench) comprise two types of floral spikelets (grass flowers). Only sessile spikelets (SSs) are capable of producing viable grains, whereas pedicellate spikelets (PSs) cease development after initiation and eventually abort. Consequently, grain number per panicle (GNP) is lower than the total number of flowers produced per panicle. The mechanism underlying this differential fertility is not well understood. To investigate this issue, we isolated a series of EMS-induced multiseeded (msd) mutants that result in full spikelet fertility, effectively doubling GNP. Previously, we showed that MSD1 is a TCP (Teosinte branched/Cycloidea/PCF) transcription factor that regulates jasmonic acid (JA) biosynthesis, and ultimately floral sex organ development. Here, we show that MSD2 encodes a lipoxygenase (LOX) that catalyzes the first committed step of JA biosynthesis. Further, we demonstrate that MSD1 binds to the promoters of MSD2 and other JA pathway genes. Together, these results show that a JA-induced module regulates sorghum panicle development and spikelet fertility. The findings advance our understanding of inflorescence development and could lead to new strategies for increasing GNP and grain yield in sorghum and other cereal crops.SignificanceThrough a single base pair mutation, grain number can be increased by ~200% in the globally important crop Sorghum bicolor. This mutation affects the expression of an enzyme, MSD2, that catalyzes the jasmonic acid pathway in developing floral meristems. The global gene expression profile in this enzymatic mutant is similar to that of a transcription factor mutant, msd1, indicating that disturbing any component of this regulatory module disrupts a positive feedback loop that occurs normally due to regular developmental perception of jasmonic acid. Additionally, the MSD1 transcription factor is able to regulate MSD2 in addition to other jasmonic acid pathway genes, suggesting that it is a primary transcriptional regulator of this hormone signaling pathway in floral meristems.

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Sorghum MSD3 Encodes an ω-3 Fatty Acid Desaturase that Increases Grain Number by Reducing Jasmonic Acid Levels

International Journal of Molecular Sciences ◽

10.3390/ijms20215359 ◽

2019 ◽

Vol 20 (21) ◽

pp. 5359 ◽

Cited By ~ 5

Author(s):

Lavanya Dampanaboina ◽

Yinping Jiao ◽

Junping Chen ◽

Nicholas Gladman ◽

Ratan Chopra ◽

...

Keyword(s):

Fatty Acid ◽

Jasmonic Acid ◽

Linolenic Acid ◽

Sequence Data ◽

Fatty Acid Desaturase ◽

Fold Increase ◽

Cereal Crops ◽

Grain Number ◽

Genomic Editing ◽

Grain Number Per Panicle

Grain number per panicle is an important component of grain yield in sorghum (Sorghum bicolor (L.)) and other cereal crops. Previously, we reported that mutations in multi-seeded 1 (MSD1) and MSD2 genes result in a two-fold increase in grain number per panicle due to the restoration of the fertility of the pedicellate spikelets, which invariably abort in natural sorghum accessions. Here, we report the identification of another gene, MSD3, which is also involved in the regulation of grain numbers in sorghum. Four bulked F2 populations from crosses between BTx623 and each of the independent msd mutants p6, p14, p21, and p24 were sequenced to 20× coverage of the whole genome on a HiSeq 2000 system. Bioinformatic analyses of the sequence data showed that one gene, Sorbi_3001G407600, harbored homozygous mutations in all four populations. This gene encodes a plastidial ω-3 fatty acid desaturase that catalyzes the conversion of linoleic acid (18:2) to linolenic acid (18:3), a substrate for jasmonic acid (JA) biosynthesis. The msd3 mutants had reduced levels of linolenic acid in both leaves and developing panicles that in turn decreased the levels of JA. Furthermore, the msd3 panicle phenotype was reversed by treatment with methyl-JA (MeJA). Our characterization of MSD1, MSD2, and now MSD3 demonstrates that JA-regulated processes are critical to the msd phenotype. The identification of the MSD3 gene reveals a new target that could be manipulated to increase grain number per panicle in sorghum, and potentially other cereal crops, through the genomic editing of MSD3 functional orthologs.

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Next Generation Cereal Crop Yield Enhancement: From Knowledge of Inflorescence Development to Practical Engineering by Genome Editing

International Journal of Molecular Sciences ◽

10.3390/ijms22105167 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5167

Author(s):

Lei Liu ◽

Penelope L. Lindsay ◽

David Jackson

Keyword(s):

Genome Editing ◽

Crop Yield ◽

Yield Enhancement ◽

Cereal Crops ◽

Grain Number ◽

Inflorescence Development ◽

New Era ◽

High Productivity ◽

Practical Engineering ◽

Crops Yield

Artificial domestication and improvement of the majority of crops began approximately 10,000 years ago, in different parts of the world, to achieve high productivity, good quality, and widespread adaptability. It was initiated from a phenotype-based selection by local farmers and developed to current biotechnology-based breeding to feed over 7 billion people. For most cereal crops, yield relates to grain production, which could be enhanced by increasing grain number and weight. Grain number is typically determined during inflorescence development. Many mutants and genes for inflorescence development have already been characterized in cereal crops. Therefore, optimization of such genes could fine-tune yield-related traits, such as grain number. With the rapidly advancing genome-editing technologies and understanding of yield-related traits, knowledge-driven breeding by design is becoming a reality. This review introduces knowledge about inflorescence yield-related traits in cereal crops, focusing on rice, maize, and wheat. Next, emerging genome-editing technologies and recent studies that apply this technology to engineer crop yield improvement by targeting inflorescence development are reviewed. These approaches promise to usher in a new era of breeding practice.

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Genetic diversity study of sorghum (Sorghum bicolor (L.) Moenc) genotypes, Ethiopia

Acta Universitatis Sapientiae Agriculture and Environment ◽

10.1515/ausae-2017-0004 ◽

2017 ◽

Vol 9 (1) ◽

pp. 44-54 ◽

Cited By ~ 1

Author(s):

Kassahun Tesfaye

Keyword(s):

Sorghum Bicolor ◽

Genetic Resource ◽

Quality Analysis ◽

Cereal Crops ◽

New Variety ◽

The World ◽

Augmented Design ◽

Genetic Diversity Study ◽

Sorghum Bicolor L ◽

Diversity Study

Abstract Sorghum bicolor is one of the most important cereal crops around the world, particularly in Africa, highly cultivated for dietary staple. For this reason, a good knowledge and usage of this genetic resource in sorghum accessions is highly vital for improving crop quality. Analysis of genetic variability among the accessions will enable accurate results in breeding. The research design used was augmented design, which is common in many gene banks. This research finding would be used later by plant breeders to select best performers for further evaluation of the crop and obtain a new variety of sorghum.

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Sorghum and millet as alternative grains in nutrition

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/69/1795 ◽

2016 ◽

pp. 91-95

Author(s):

Szintia Jevcsák ◽

Péter Sipos

Keyword(s):

Corn Starch ◽

Alcoholic Beverages ◽

Cereal Crops ◽

Total Phenol Content ◽

Panicum Miliaceum ◽

Mineral Contents ◽

Positive Effects ◽

Glucose Syrup ◽

Grain Products ◽

Sorghum Bicolor L

Sorghum (Sorghum bicolor L.) and millet (Panicum miliaceum L.) are the fifth and sixth most important cereal crops in the world. Gluten-free grains, therefore persons with coeliac disease could consume them also. In addition, they have a lot of positive effects due to their phenolic compounds (phenol acid, flavonoid, tannin). The total phenol content of sorghum is high, but Panicum miliaceum and Eleusine coracana have higher antioxidant activity. Fiber and mineral contents are also high, the protein contents are also higher than in standard cereals. Sorghum use is similar to corn: starch, glucose, syrup, and oil can be produced. Moreover, it can be used in preparing whole grain products, bread, pancake, dumpling, mush, cake, pasta and beer from sorghum. Broom and forage are also can be prepeared from them. Millet used such as mush, steamed food, cake, bread, alcoholic and non-alcoholic beverages.

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MSD1 regulates pedicellate spikelet fertility in sorghum through the jasmonic acid pathway

Nature Communications ◽

10.1038/s41467-018-03238-4 ◽

2018 ◽

Vol 9 (1) ◽

Cited By ~ 22

Author(s):

Yinping Jiao ◽

Young Koung Lee ◽

Nicholas Gladman ◽

Ratan Chopra ◽

Shawn A. Christensen ◽

...

Keyword(s):

Jasmonic Acid ◽

Spikelet Fertility ◽

Acid Pathway

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The Coordinated KNR6–AGAP–ARF1 Complex Modulates Vegetative and Reproductive Traits by Participating in Vesicle Trafficking in Maize

Cells ◽

10.3390/cells10102601 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2601

Author(s):

Manfei Li ◽

Ran Zhao ◽

Yanfang Du ◽

Xiaomeng Shen ◽

Qiang Ning ◽

...

Keyword(s):

Golgi Apparatus ◽

Vesicle Trafficking ◽

Reproductive Traits ◽

Adenosine Diphosphate ◽

Loss Of Function ◽

Kernel Number ◽

Inflorescence Development ◽

Regulatory Module ◽

Agronomically Important Traits ◽

Insight Into

The KERNEL NUMBER PER ROW6 (KNR6)-mediated phosphorylation of an adenosine diphosphate ribosylation factor (Arf) GTPase-activating protein (AGAP) forms a key regulatory module for the numbers of spikelets and kernels in the ear inflorescences of maize (Zea mays L.). However, the action mechanism of the KNR6–AGAP module remains poorly understood. Here, we characterized the AGAP-recruited complex and its roles in maize cellular physiology and agronomically important traits. AGAP and its two interacting Arf GTPase1 (ARF1) members preferentially localized to the Golgi apparatus. The loss-of-function AGAP mutant produced by CRISPR/Cas9 resulted in defective Golgi apparatus with thin and compact cisternae, together with delayed internalization and repressed vesicle agglomeration, leading to defective inflorescences and roots, and dwarfed plants with small leaves. The weak agap mutant was phenotypically similar to knr6, showing short ears with fewer kernels. AGAP interacted with KNR6, and a double mutant produced shorter inflorescence meristems and mature ears than the single agap and knr6 mutants. We hypothesized that the coordinated KNR6–AGAP–ARF1 complex modulates vegetative and reproductive traits by participating in vesicle trafficking in maize. Our findings provide a novel mechanistic insight into the regulation of inflorescence development, and ear length and kernel number, in maize.

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