miR156 regulates somatic embryogenesis by modulating starch accumulation in citrus
Meng-Qi Feng1, Meng-Di Lu1, Jian-Mei Long1
1Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China.
Journal of Experimental Botany
|June 6, 2022
Summary
Transcription factors CsAGL15 and CsFUS3 activate citrus somatic embryogenesis (SE) by upregulating csi-miR156a. This microRNA represses CsSPL genes, influencing starch synthesis and SE efficiency.
Area of Science:
- Plant Biotechnology
- Molecular Biology
- Developmental Biology
Background:
- Somatic embryogenesis (SE) is crucial for citrus regeneration but often faces recalcitrance.
- Previous studies identified miR156-SPL modules regulating SE in citrus callus.
- The downstream regulatory pathway of miR156-SPL in SE remained largely unknown.
Purpose of the Study:
- To elucidate the downstream regulatory pathway of the miR156-SPL module in citrus somatic embryogenesis.
- To identify key transcription factors and genes involved in SE regulation.
- To provide insights for enhancing SE efficiency in citrus.
Main Methods:
- Analysis of transcription factor binding to the CsMIR156A promoter.
- Gene expression analysis using quantitative PCR (qPCR).
- Overexpression of short tandem target mimic (STTM)-miR156a to suppress endogenous miR156a function.
- Assessment of amyloplasts and starch content in callus cells.
Main Results:
- Transcription factors CsAGL15 and CsFUS3 were found to activate CsMIR156A expression.
- Suppression of csi-miR156a led to increased CsSPL gene expression and reduced SE efficiency.
- Overexpression of STTM-miR156a decreased amyloplasts and starch content, downregulating starch synthesis genes.
- csi-miR172d was downregulated, while its target genes CsTOE1.1 and CsTOE1.2 were upregulated, inhibiting starch biosynthesis.
Conclusions:
- A working model proposes CsAGL15 and CsFUS3 activate csi-miR156a, which represses CsSPLs.
- This pathway further regulates csi-miR172d and CsTOEs, impacting starch accumulation and SE in citrus.
- The study clarifies the miR156-SPL and miR172-TOE mediated regulation of SE, offering strategies to improve citrus regeneration.
Related Concept Videos
03:02Primary and Secondary Growth in Roots and Shoots
58.2K
Vascular plants, which account for over 90% of the Earth’s vegetation, all undergo primary growth—which lengthens roots and shoots. Many land plants, notably woody plants, also undergo secondary growth—which thickens roots and shoots.
58.2K
02:04Regulation of Transpiration by Stomata
29.2K
During photosynthesis, plants acquire the necessary carbon dioxide and release the produced oxygen back into the atmosphere. Openings in the epidermis of plant leaves is the site of this exchange of gasses. A single opening is called a stoma—derived from the Greek word for “mouth.” Stomata open and close in response to a variety of environmental cues.
29.2K
01:17Gene Regulation During Sporulation
88
Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
88
02:36Meristems and Plant Growth
47.1K
Plants grow throughout their lives; this is called indeterminate growth, and it distinguishes plants from most animals. Although certain parts of plants stop growing (e.g., leaves and flowers), others grow continuously—like roots and stems.
47.1K
01:10Zygotic Development And Stem Cell Formation
5.5K
The development of all multicellular organisms starts with the fusion of haploid cells called sperm and egg to form a diploid zygote. A zygote is a totipotent cell that can develop into a complete organism. The zygote undergoes cell division or cleavage to form an 8-cell mass. Until this stage, the cells are spherical, loosely attached, and remain totipotent. Totipotent cells are capable of developing both the embryonic and the extraembryonic tissues. However, as they continue to divide, they...
5.5K
01:58Fruit Development, Structure, and Function
23.1K
Fruits form from a mature flower ovary. As seeds develop from the ovules contained within, the ovary wall undergoes a series of complex changes to form fruit. In some fruits, such as soybeans, the ovary wall dries; in other fruits, such as grapes, it remains fleshy. In some cases, organs other than the ovary contribute to fruit formation; such fruits are called accessory fruits.
23.1K