ArticleThe Plant cell2008
Beta-AMYLASE4, a noncatalytic protein required for starch breakdown, acts upstream of three active beta-amylases in Arabidopsis chloroplasts.
Article in The Plant cell, 2008. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 160 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
160 citing papers in PubMed, 1 synthesis or guideline pooled it, 379 citations in OpenAlex.
- Diurnal changes of polysome loading track sucrose content in the rosette of wild-type arabidopsis and the starchless pgm mutant.Plant physiology · 2013Pooled it
- Combined linkage mapping and association analysis reveal the genetic control of starch content in maize kernel.TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik · 2026Article
- Starch phosphorylase acts as a pivotal scaffold connecting starch metabolism enzymes with photosystem I subunits.Plant & cell physiology · 2026Article
- Starch Degradation and Soluble Sugar Accumulation Are Associated with Cold Tolerance in Winter Rapeseed (Plants (Basel, Switzerland) · 2026Article
- Regulatory factors of starch metabolism in cereal endosperm.Plant molecular biology · 2026Review
- The MdERF17-MdbHLH149 Module Mediates Ethylene-Induced Starch Degradation Through the Transcriptional Repression of α-Amylase MdAMY1 in Apple.Plant biotechnology journal · 2026Article
- Pangenome-assisted characterization of TaBAM genes and association of TaBAM16-1B with NDVI in wheat.TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik · 2026Article
- BolAG-BolRPI2-BolBAM4 Module Regulates the Bolting of Curd by Modulating Starch Metabolism in Broccoli (Brassica oleracea var. italica).Plant biotechnology journal · 2026Article
- A structural perspective on α-glucan catabolism in oxygenic phototrophs.The Plant journal : for cell and molecular biology · 2026Review
- Root-enriched β-amylase GmBAM-like 1 enhances drought and salt tolerance in Arabidopsis.Genetics and molecular biology · 2026Article
- SlCV affects starch metabolism by regulating SlBAM3 stability under low night temperature stress in tomatoes.Horticulture research · 2025Article
- Functional Characterization of Arabidopsis α-Amylase3 (AMY3): Amylose Specificity and Structural Insights into Its Duplex Carbohydrate-Binding Module.bioRxiv : the preprint server for biology · 2025Article
- The Pseudoenzyme β-Amylase9 From Arabidopsis Activates α-Amylase3: A Possible Mechanism to Promote Stress-Induced Starch Degradation.Proteins · 2025Article
- Genome-wide identification of the AcBAM family in kiwifruit (Actinidia chinensis cv. Hongyang) and the expression profiling analysis of AcBAMs reveal their role in starch metabolism.BMC plant biology · 2025Article
- Article
- Target of rapamycin signaling regulates starch degradation via α-glucan water dikinase in a unicellular red alga.Plant physiology · 2025Article
- Genome-wide analysis of the FKBP gene family and the potential role of GhFKBP 13 in chloroplast biogenesis in upland cotton.BMC genomics · 2025Article
- Application of starch-degradation bacteria in cigar tobacco leaf fermentation: effects on starch degradation, microbial communities and metabolic pathways.Frontiers in microbiology · 2025Article
- Exploring the metabolic daylength measurement system: implications for photoperiodic growth.The New phytologist · 2025Review
- Article
100 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
15 authors at 5 institutions in 3 countries.
Funding
Abstract
This work investigated the roles of beta-amylases in the breakdown of leaf starch. Of the nine beta-amylase (BAM)-like proteins encoded in the Arabidopsis thaliana genome, at least four (BAM1, -2, -3, and -4) are chloroplastic. When expressed as recombinant proteins in Escherichia coli, BAM1, BAM2, and BAM3 had measurable beta-amylase activity but BAM4 did not. BAM4 has multiple amino acid substitutions relative to characterized beta-amylases, including one of the two catalytic residues. Modeling predicts major differences between the glucan binding site of BAM4 and those of active beta-amylases. Thus, BAM4 probably lost its catalytic capacity during evolution. Total beta-amylase activity was reduced in leaves of bam1 and bam3 mutants but not in bam2 and bam4 mutants. The bam3 mutant had elevated starch levels and lower nighttime maltose levels than the wild type, whereas bam1 did not. However, the bam1 bam3 double mutant had a more severe phenotype than bam3, suggesting functional overlap between the two proteins. Surprisingly, bam4 mutants had elevated starch levels. Introduction of the bam4 mutation into the bam3 and bam1 bam3 backgrounds further elevated the starch levels in both cases. These data suggest that BAM4 facilitates or regulates starch breakdown and operates independently of BAM1 and BAM3. Together, our findings are consistent with the proposal that beta-amylase is a major enzyme of starch breakdown in leaves, but they reveal unexpected complexity in terms of the specialization of protein function.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.