Incomplete filling in the basal region of maize endosperm: timing of development of starch synthesis and cell vitality.

Starch synthesis in maize endosperm adheres to the basipetal sequence from the apex downwards. However, the mechanism underlying nonuniformity among regions of the endosperm in starch accumulation and its significance is poorly understood. Here, we examined the spatiotemporal transcriptomes and starch accumulation dynamics in apical (AE), middle (ME), and basal (BE) regions of endosperm throughout the filling stage. Results demonstrated that the BE had lower levels of gene transcripts and enzymes facilitating starch synthesis, corresponding to incomplete starch storage at maturity, compared with AE and ME. Contrarily, the BE showed abundant gene expression for genetic processing and slow progress in physiological development (quantified by an index calculated from the expression values of development progress marker genes), revealing a sustained cell vitality of the BE. Further analysis demonstrated a significant parabolic correlation between starch synthesis and physiological development. An in-depth examination showed that the BE had more active signaling pathways of IAA and ABA than the AE throughout the filling stage, while ethylene showed the opposite pattern. Besides, SNF1-related protein kinase1 (SnRK1) activity, a regulator for starch synthesis modulated by trehalose-6-phosphate (T6P) signaling, was kept at a lower level in the BE than the AE and ME, corresponding to the distinct gene expression in the T6P pathway in starch synthesis regulation. Collectively, the findings support an improved understanding of the timing of starch synthesis and cell vitality in regions of the endosperm during development, and potential regulation from hormone signaling and T6P/SnRK1 signaling.

Exogenous abscisic acid (ABA) improves the filling process of maize grains at different ear positions by promoting starch accumulation and regulating hormone levels under high planting density.

BACKGROUND: Higher planting densities typically cause a decline in grain weight, limiting the potential for high maize yield. Additionally, variations in grain filling occur at different positions within the maize ear. Abscisic acid (ABA) is important for grain filling and regulates grain weight. However, the effects of exogenous ABA on the filling process of maize grains at different ear positions under high planting density are poorly understood. In this study, two summer maize hybrids (DengHai605 (DH605) and ZhengDan958 (ZD958)) commonly grown in China were used to examine the effects of ABA application during the flowering stage on grain filling properties, starch accumulation, starch biosynthesis associated enzyme activities, and hormone levels of maize grain (including inferior grain (IG) and superior grain (SG)) under high planting density. RESULTS: Our results showed that exogenous ABA significantly increased maize yield, primarily owing to a higher grain weight resulting from an accelerated grain filling rate relative to the control. There was no significant difference in yield between DH605 and ZD958 in the control and ABA treatments. Moreover, applying ABA promoted starch accumulation by raising the activities of sucrose synthase, ADP-glucose pyrophosphorylase, granule-bound starch synthases, soluble starch synthase, and starch branching enzyme in grains. It also increased the levels of zeatin riboside, indole-3-acetic acid, and ABA and decreased the level of gibberellin in grains, resulting in more efficient grain filling. Notably, IG exhibited a less efficient filling process compared to SG, probably due to lower starch biosynthesis associated enzyme activities and an imbalance in hormone contents. Nevertheless, IG displayed greater sensitivity to exogenous ABA than SG, suggesting that appropriate cultural measures to improve IG filling may be a viable strategy to further increase maize yield. CONCLUSIONS: According to our results, spraying exogenous ABA could effectively improve grain filling properties, accelerate starch accumulation by increasing relevant enzyme activities, and regulate hormone levels in grains, resulting in higher grain weight and yield of maize under high planting density. Our findings offer more evidence for using exogenous hormones to improve maize yield under high planting density.

Plasma membrane-localized SEM1 protein mediates sugar movement to sink rice tissues.

The translocation of photosynthate carbohydrates, such as sucrose, is critical for plant growth and crop yield. Previous studies have revealed that sugar transporters, plasmodesmata and sieve plates act as important controllers in sucrose loading into and unloading from phloem in the vascular system. However, other pivotal steps for the regulation of sucrose movement remain largely elusive. In this study, characterization of two starch excesses in mesophyll (sem) mutants and dye and sucrose export assays were performed to provide insights into the regulatory networks that drive source-sink relations in rice. Map-based cloning identified two allelic mutations in a gene encoding a GLUCAN SYNTHASE-LIKE (GSL) protein, thus indicating a role for SEM1 in callose biosynthesis. Subcellular localization in rice showed that SEM1 localized to the plasma membrane. In situ expression analysis and GUS staining showed that SEM1 was mainly expressed in vascular phloem cells. Reduced sucrose transport was found in the sem1-1/1-2 mutant, which led to excessive starch accumulation in source leaves and inhibited photosynthesis. Paraffin section and transmission electron microscopy experiments revealed that less-developed vascular cells (VCs) in sem1-1/1-2 potentially disturbed sugar movement. Moreover, dye and sugar trafficking experiments revealed that aberrant VC development was the main reason for the pleiotropic phenotype of sem1-1/1-2. In total, efficient sucrose loading into the phloem benefits from an optional number of VCs with a large vacuole that could act as a buffer holding tank for sucrose passing from the vascular bundle sheath.

Magnesium chelatase subunit D is not only required for chlorophyll biosynthesis and photosynthesis, but also affecting starch accumulation in Manihot esculenta Crantz.

BACKGROUND: Magnesium chelatase plays an important role in photosynthesis, but only a few subunits have been functionally characterized in cassava. RESULTS: Herein, MeChlD was successfully cloned and characterized. MeChlD encodes a magnesium chelatase subunit D, which has ATPase and vWA conservative domains. MeChlD was highly expressed in the leaves. Subcellular localization suggested that MeChlD:GFP was a chloroplast-localized protein. Furthermore, the yeast two-hybrid system and BiFC analysis indicated that MeChlD interacts with MeChlM and MePrxQ, respectively. VIGS-induce silencing of MeChlD resulted in significantly decreased chlorophyll content and reduction the expression of photosynthesis-related nuclear genes. Furthermore, the storage root numbers, fresh weight and the total starch content in cassava storage roots of VIGS-MeChlD plants was significantly reduced. CONCLUSION: Taken together, MeChlD located at the chloroplast is not only required for chlorophyll biosynthesis and photosynthesis, but also affecting the starch accumulation in cassava. This study expands our understanding of the biological functions of ChlD proteins.

Integrated Metabolomic and Transcriptomic Analyses Reveals Sugar Transport and Starch Accumulation in Two Specific Germplasms of Manihot esculenta Crantz.

As a starchy and edible tropical plant, cassava (Manihot esculenta Crantz) has been widely used as an industrial raw material and a dietary source. However, the metabolomic and genetic differences in specific germplasms of cassava storage root were unclear. In this study, two specific germplasms, M. esculenta Crantz cv. sugar cassava GPMS0991L and M. esculenta Crantz cv. pink cassava BRA117315, were used as research materials. Results showed that sugar cassava GPMS0991L was rich in glucose and fructose, whereas pink cassava BRA117315 was rich in starch and sucrose. Metabolomic and transcriptomic analysis indicated that sucrose and starch metabolism had significantly changing metabolites enrichment and the highest degree of differential expression genes, respectively. Sugar transport in storage roots may contribute to the activities of sugar, which will eventually be exported to transporters (SWEETs), such as (MeSWEET1a, MeSWEET2b, MeSWEET4, MeSWEET5, MeSWEET10b, and MeSWEET17c), which transport hexose to plant cells. The expression level of genes involved in starch biosynthesis and metabolism were altered, which may result in starch accumulation. These results provide a theoretical basis for sugar transport and starch accumulation and may be useful in improving the quality of tuberous crops and increasing yield.

Over-Expression of Phosphoserine Aminotransferase-Encoding Gene (AtPSAT1) Prompts Starch Accumulation in L. turionifera under Nitrogen Starvation.

It has been demonstrated that the phosphorylation pathway of L-serine (Ser) biosynthesis (PPSB) is very important in plant growth and development, but whether and how PPSB affects nitrogen metabolism and starch accumulation has not been fully elucidated. In this study, we took the energy plant duckweed (strain Lemna turionifera 5511) as the research object and used a stable genetic transformation system to heterologously over-expressing Arabidopsis AtPSAT1 (the gene encoding phosphoserine aminotransferase, the second enzyme of PPSB). Our results showed that, under nitrogen starvation, the transgenic plants grew faster, with higher values of Fv/Fm, rETR, and Y(II), as well as fresh and dry weight, than the wild-type. More promisingly, the accumulation of starch was also found to be significantly improved when over-expressing AtPSAT1 in the transgenic plants. qRT-PCR analysis results showed that the expression of genes related to nitrogen assimilation, carbon metabolism, and starch biosynthesis was up-regulated, while the expression of starch degradation-related genes was down-regulated by AtPSAT1 over-expression. We propose that the increased starch accumulation caused by AtPSAT1 over-expression may result from both elevated photosynthetic capacity and nitrogen utilization efficiency. This research sheds new light on the mechanism underlying the ability of PPSB to coordinate nitrogen and carbon metabolism, and provides a feasible way to improve starch production, that is, through engineering PPSB in crops.

Developmental plasticity of Arabidopsis hypocotyl is dependent on exocyst complex function.

The collet (root-hypocotyl junction) region is an important plant transition zone between soil and atmospheric environments. Despite its crucial importance for plant development, little is known about how this transition zone is specified. Here we document the involvement of the exocyst complex in this process. The exocyst, an octameric tethering complex, participates in secretion and membrane recycling and is central to numerous cellular and developmental processes, such as growth of root hairs, cell expansion, recycling of PIN auxin efflux carriers and many others. We show that dark-grown Arabidopsis mutants deficient in exocyst subunits can form a hair-bearing ectopic collet-like structure above the true collet, morphologically resembling the true collet but also retaining some characteristics of the hypocotyl. The penetrance of this phenotypic defect is significantly influenced by cultivation temperature and carbon source, and is related to a defect in auxin regulation. These observations provide new insights into the regulation of collet region formation and developmental plasticity of the hypocotyl.

Sucrose Synthase Enhances Hull Size and Grain Weight by Regulating Cell Division and Starch Accumulation in Transgenic Rice.

Grain size and weight are two important determinants of grain yield in rice. Although overexpression of sucrose synthase (SUS) genes has led to several improvements on cellulose and starch-based traits in transgenic crops, little is reported about SUS enhancement of hull size and grain weight in rice. In this study, we selected transgenic rice plants that overexpressed OsSUS1-6 genes driven with the maize Ubi promoter. Compared to the controls (wild type and empty vector line), all independent OsSUS homozygous transgenic lines exhibited considerably increased grain yield and grain weights. Using the representative OsSUS3 overexpressed transgenic plants, four independent homozygous lines showed much raised cell numbers for larger hull sizes, consistent with their enhanced primary cell wall cellulose biosynthesis and postponed secondary wall synthesis. Accordingly, the OsSUS3 transgenic lines contained much larger endosperm volume and higher starch levels than those of the controls in the mature grains, leading to increased brown grain weights by 15-19%. Hence, the results have demonstrated that OsSUS overexpression could significantly improve hull size and grain weight by dynamically regulating cell division and starch accumulation in the transgenic rice.

Spatio-temporal patterning of arginyl-tRNA protein transferase (ATE) contributes to gametophytic development in a moss.

The importance of the arginyl-tRNA protein transferase (ATE), the enzyme mediating post-translation arginylation of proteins in the N-end rule degradation (NERD) pathway of protein stability, was analysed in Physcomitrella patens and compared to its known functions in other eukaryotes. We characterize ATE:GUS reporter lines as well as ATE mutants in P. patens to study the impact and function of arginylation on moss development and physiology. ATE protein abundance is spatially and temporally regulated in P. patens by hormones and light and is highly abundant in meristematic cells. Further, the amount of ATE transcript is regulated during abscisic acid signalling and downstream of auxin signalling. Loss-of-function mutants exhibit defects at various levels, most severely in developing gametophores, in chloroplast starch accumulation and senescence. Thus, arginylation is necessary for moss gametophyte development, in contrast to the situation in flowering plants. Our analysis further substantiates the conservation of the N-end rule pathway components in land plants and highlights lineage-specific features. We introduce moss as a model system to characterize the role of the NERD pathway as an additional layer of complexity in eukaryotic development.

Structure and expression analysis of genes encoding ADP-glucose pyrophosphorylase large subunit in wheat and its relatives.

ADP-glucose pyrophosphorylase (AGP), which consists of two large subunits (AGP-L) and two small subunits (AGP-S), controls the rate-limiting step in the starch biosynthetic pathway. In this study, a full-length open reading frame (ORF) of AGP-L gene (named as Agp2) in wheat and a series of Agp2 gene sequences in wheat relatives were isolated. The coding region of Agp2 contained 15 exons and 14 introns including a full-length ORF of 1566 nucleotides, and the deduced protein contained 522 amino acids (57.8 kDa). Generally, the phylogenetic tree of Agp2 indicated that sequences from A- and D-genome donor species were most similar to each other and sequences from B-genome donor species contained more variation. Starch accumulation and Agp2 expression in wheat grains reached their peak at 21 and 15 days post anthesis (DPA), respectively.

Receptor protein kinase FERONIA controls leaf starch accumulation by interacting with glyceraldehyde-3-phosphate dehydrogenase.

Cell expansion is coordinated by several cues, but available energy is the major factor determining growth. Receptor protein kinase FERONIA (FER) is a master regulator of cell expansion, but the details of its control mechanisms are not clear. Here we show that FER interacts with cytosolic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH, GAPC1 and GAPC2), that catalyzes a key reaction in glycolysis, which contributes to energy production. When there is an FER deficiency, there are corresponding decreases in the enzyme activity of GAPDH and increased amounts of starch. More importantly, gapc1/2 mutants mimic fer4 mutants. These data indicate that FER regulated starch content is an evolutionarily conserved function in plants that connects the cell expansion and energy metabolism pathways.

Photosynthesis, sucrose metabolism, and starch accumulation in two NILs of winter wheat.

The photosynthetic oxygen evolution rate, Hill reaction activity of seedlings and photosynthetic parameter, Pn-Ci curve and some source-sink metabolism-related enzyme activities, and substance content of flag leaves were measured by using two wheat near isogenic lines with significant differences in the photosynthetic rate of the 154 (high photosynthetic rate) and 212 (low photosynthetic rate) lines as materials. The results showed that the maximal carboxylation efficiency (Vcmax) and Hill reaction activity were higher in line 154 than that of line 212. The Pn in flag leaves of line 154 was significantly higher than that of line 212 during the anthesis to grain-filling stage. Higher leaf sucrose phosphate synthase activity, grain sucrose synthase activity, and grain ADPG pyrophosphorylase activity ensured that the photosynthate of line 154 could be transported to grains and translated into starch in a timely and effective manner, which also contributed to the maintenance of its high photosynthetic rate. Eventually, all of these factors of line 154 resulted in its higher grain yield compared with the low photosynthetic rate of line 212.

Tocopherol deficiency reduces sucrose export from salt-stressed potato leaves independently of oxidative stress and symplastic obstruction by callose.

Tocopherol cyclase, encoded by the gene SUCROSE EXPORT DEFECTIVE1, catalyses the second step in the synthesis of the antioxidant tocopherol. Depletion of SXD1 activity in maize and potato leaves leads to tocopherol deficiency and a 'sugar export block' phenotype that comprises massive starch accumulation and obstruction of plasmodesmata in paraveinal tissue by callose. We grew two transgenic StSXD1:RNAi potato lines with severe tocopherol deficiency under moderate light conditions and subjected them to salt stress. After three weeks of salt exposure, we observed a strongly reduced sugar exudation rate and a lack of starch mobilization in leaves of salt-stressed transgenic plants, but not in wild-type plants. However, callose accumulation in the vasculature declined upon salt stress in all genotypes, indicating that callose plugging of plasmodesmata was not the sole cause of the sugar export block phenotype in tocopherol-deficient leaves. Based on comprehensive gene expression analyses, we propose that enhanced responsiveness of SnRK1 target genes in mesophyll cells and altered redox regulation of phloem loading by SUT1 contribute to the attenuation of sucrose export from salt-stressed SXD:RNAi source leaves. Furthermore, we could not find any indication that elevated oxidative stress may have served as a trigger for the salt-induced carbohydrate phenotype of SXD1:RNAi transgenic plants. In leaves of the SXD1:RNAi plants, sodium accumulation was diminished, while proline accumulation and pools of soluble antioxidants were increased. As supported by phytohormone contents, these differences seem to increase longevity and prevent senescence of SXD:RNAi leaves under salt stress.

Comparative Transcriptome and sRNAome Analysis Suggest Coordinated Citrus Immune Responses against Huanglongbing Disease.

Citrus Huanglongbing (HLB), caused by the phloem-inhibiting bacterium Candidatus Liberibacter asiaticus (CLas), is the most devastating citrus disease, intimidating citrus production worldwide. Although commercially cultivated citrus cultivars are vulnerable to CLas infection, HLB-tolerant attributes have, however, been observed in certain citrus varieties, suggesting a possible pathway for identifying innate defense regulators that mitigate HLB. By adopting transcriptome and small RNAome analysis, the current study compares the responses of HLB-tolerant lemon (Citrus limon L.) with HLB-susceptible Shatangju mandarin (Citrus reticulata Blanco cv. Shatangju) against CLas infection. Transcriptome analysis revealed significant differences in gene expression between lemon and Shatangju. A total of 1751 and 3076 significantly differentially expressed genes were identified in Shatangju and lemon, respectively. Specifically, CLas infected lemon tissues demonstrated higher expressions of genes involved in antioxidant enzyme activity, protein phosphorylation, carbohydrate, cell wall, and lipid metabolism than Shatangju. Wet-lab experiments further validated these findings, demonstrating increased antioxidant enzyme activity in lemon: APX (35%), SOD (30%), and CAT (64%) than Shatangju. Conversely, Shatangju plants exhibited higher levels of oxidative stress markers like H2O2 (44.5%) and MDA content (65.2%), alongside pronounced ion leakage (11.85%), than lemon. Moreover, microscopic investigations revealed that CLas infected Shatangju phloem exhibits significantly more starch and callose accumulation than lemon. Furthermore, comparative sRNA profiles revealed the potential defensive regulators for HLB tolerance. In Shatangju, increased expression of csi-miR166 suppresses the expression of disease-resistant proteins, leading to inadequate defense against CLas. Conversely, reduced expression of csi-miR166 in lemon plants enables them to combat HLB by activating disease-resistance proteins. The above findings indicate that when infected with CLas, lemon exhibits stronger antioxidative activity and higher expression of disease-resistant genes, contributing to its enhanced tolerance to HLB. In contrast, Shatangju shows lower antioxidative activity, reduced expression of disease-resistant genes, significant ion leakage, and extensive callose deposition, possibly related to damage to plant cell structure and blockage of phloem sieve tubes, thereby promoting the development of HLB symptoms.

[Effects of N, P, and K application rates on distribution of 13C assimilates, starch accumulation in grains and fertilizer utilization of wheat]. / 氮磷钾施用量对小麦旗叶13CåŒåŒ–ç‰©åˆ†é ã€ç±½ç²’æ·€ç²‰ç§¯ç´¯å’Œè‚¥æ–™åˆ©ç”¨çš„å½±å“.

Clarifying the appropriate application rates of N, P, and K fertilizers and the physiological mechanisms of wheat under water-saving recharge irrigation in the North China Plain would provide a theoretical basis for formulating reasonable fertilization plans for high-yield and high-efficiency wheat production. We established four treatments with different amounts of nitrogen (N), phosphorus (P2O5), and potassium (K2O) application: 0, 0, and 0 kg·hm-2 (F0), 180, 75, and 60 kg·hm-2 (F1), 225, 120, and 105 kg·hm-2 (F2), and 270, 165, and 150 kg·hm-2 (F3). During the jointing and anthesis stages of wheat, the relative water content of each treatment in the 0-40 cm soil layer was replenished to 70%, to investigate the differences in wheat flag leaf photosynthetic characteristics, distribution of 13C assimilates, grain starch accumulation, and fertilizer utilization. The results showed that the relative chlorophyll content of flag leaves, photosynthetic and chlorophyll fluorescence parameters, 13C assimilate allocation in each organ, enzyme activities involved in starch synthesis, and starch accumulation in the F1 treatment were significantly higher than that in F0 treatment, which was an important physiological basis for the 20.9% increase in grain yield. The above parameters and yield in the F2 and F3 treatments showed no significant increase compared to F1 treatment, while fertilizer productivity and agronomic efficiency of N, P, and K decreased by 17.5%-58.4% and 12.7%-50.7%, respectively. Therefore, F1 could promote flag leaf photosynthetic assimilate production and grain starch accumulation under water-saving supplementary irrigation conditions, resulting in higher grain yield and fertilizer utilization efficiency.

Programmed cell death during quinoa perisperm development.

At seed maturity, quinoa (Chenopodium quinoa Willd.) perisperm consists of uniform, non-living, thin-walled cells full of starch grains. The objective of the present study was to study quinoa perisperm development and describe the programme of cell death that affects the entire tissue. A number of parameters typically measured during programmed cell death (PCD), such as cellular morphological changes in nuclei and cytoplasm, endoreduplication, DNA fragmentation, and the participation of nucleases and caspase-like proteases in nucleus dismantling, were evaluated; morphological changes in cytoplasm included subcellular aspects related to starch accumulation. This study proved that, following fertilization, the perisperm of quinoa simultaneously accumulates storage reserves and degenerates, both processes mediated by a programme of developmentally controlled cell death. The novel findings regarding perisperm development provide a starting point for further research in the Amaranthaceae genera, such as comparing seeds with and without perisperm, and specifying phylogeny and evolution within this taxon. Wherever possible and appropriate, differences between quinoa perisperm and grass starchy endosperm--a morphologically and functionally similar, although genetically different tissue--were highlighted and discussed.

Suitable nitrogen fertilizer application drives the endosperm development and starch synthesis to improve the physicochemical properties of common buckwheat grain.

The effects of nitrogen (N) fertilizer on endosperm development, starch component, key enzyme activity and grain quality of common buckwheat were investigated in this study. The results showed that N fertilization significantly enhanced the number and area of endosperm cells, and significant increases were also observed in the contents of amylose, amylopectin and total starch. With increasing N level, the activities of key enzyme significantly increased showing the maximum under the N2 level (180 kg N ha-1), and then decreased under high N level. As N level increased, the ash, crude protein and amylose content varied from 1.36 to 2.25 %, from 7.99 to 15.84 % and from 22.69 to 27.64 %, respectively. The gelatinization enthalpy significantly increased with the range of 3.46-5.66 J/g, while no change was found in crystalline structure of common buckwheat flour. These results indicated that appropriate N application could effectively improve the endosperm development, starch synthesis and accumulation, and grain properties of common buckwheat, with the best effect under the level of 180 kg N ha-1.

Overexpression of the Phosphoserine Phosphatase-Encoding Gene (AtPSP1) Promotes Starch Accumulation in Lemna turionifera 5511 under Sulfur Deficiency.

Duckweeds are well known for their high accumulation of starch under stress conditions, along with inhibited growth. The phosphorylation pathway of serine biosynthesis (PPSB) was reported as playing a vital role in linking the carbon, nitrogen, and sulfur metabolism in this plant. The overexpression of AtPSP1, the last key enzyme of the PPSB pathway in duckweed, was found to stimulate the accumulation of starch under sulfur-deficient conditions. The growth- and photosynthesis-related parameters were higher in the AtPSP1 transgenic plants than in the WT. The transcriptional analysis showed that the expression of several genes in starch synthesis, TCA, and sulfur absorption, transportation, and assimilation was significantly up- or downregulated. The study suggests that PSP engineering could improve starch accumulation in Lemna turionifera 5511 by coordinating the carbon metabolism and sulfur assimilation under sulfur-deficient conditions.

Genome-wide identification and characterization of 14-3-3 gene family related to negative regulation of starch accumulation in storage root of Manihot esculenta.

The 14-3-3 protein family is a highly conservative member of the acid protein family and plays an important role in regulating a series of important biological activities and various signal transduction pathways. The role of 14-3-3 proteins in regulating starch accumulation still remains largely unknown. To investigate the properties of 14-3-3 proteins, the structures and functions involved in starch accumulation in storage roots were analyzed, and consequently, 16 Me14-3-3 genes were identified. Phylogenetic analysis revealed that Me14-3-3 family proteins are split into two groups (ε and non-ε). All Me14-3-3 proteins contain nine antiparallel α-helices. Me14-3-3s-GFP fusion protein was targeted exclusively to the nuclei and cytoplasm. In the early stage of starch accumulation in the storage root, Me14-3-3 genes were highly expressed in high-starch cultivars, while in the late stage of starch accumulation, Me14-3-3 genes were highly expressed in low-starch cultivars. Me14-3-3 I, II, V, and XVI had relatively high expression levels in the storage roots. The transgenic evidence from Me14-3-3II overexpression in Arabidopsis thaliana and the virus-induced gene silencing (VIGS) in cassava leaves and storage roots suggest that Me14-3-3II is involved in the negative regulation of starch accumulation. This study provides a new insight to understand the molecular mechanisms of starch accumulation linked with Me14-3-3 genes during cassava storage root development.