Journal of Genetics and Genomics in 2023:progresses and beyond

Journal of Genetics and Genomics(JGG),launched in 1974,celebrates its 50th birthday in 2023.With continuous support from our authors,reviewers,readers,and the editorial board,JGG has made remarkable progress in the past year by publishing 122 papers covering major disciplines in life sciences and medical genetics with exciting discoveries.It is worthwhile to note that we have recruited 66 young talents to join JGG as junior editors,resulting in significant improvement in manuscript evaluation and journal promotion.Here,we summarize major progresses reported in JGG in 2023 fromaneditorial view.

JGG in 2022:challenges,opportunities,and prospects

During the past 2022,the Journal of Genetics and Genomics(JGG)has seen a variety of challenges as well as opportunities.At the difficult time of the COVID-19 pandemic,we have gone through unforeseen difficulties,including the cancellation of academic conferences,drop in submissions,work from home,and infections.Despite all these challenges,however,our authors,readers,reviewers,and editorial members have all supported and witnessed the progress of JGG.In 2022,JGG has published a record number of 136 papers reporting cutting-edge studies covering a range of fields in life sciences.Here,we briefly highlight important progresses in 2022 in an editorial view.

CLE25 peptide regulates phloem initiation in Arabidopsis through a CLERK-CLV2 receptor complex

The phloem, located within the vascular system, is critical for delivery of nutrients and signaling molecules throughout the plant body. Although the morphological process and several factors regulating phloem differentiation have been reported, the molecular mechanism underlying its initiation remains largely unknown. Here, we report that the small peptide-coding gene, CLAVATA 3 (CLV3)/EMBEYO SURROUNDING REGION 25 (CLE25), the expression of which begins in provascular initial cells of 64-cell-staged embryos, and continues in sieve element-procambium stem cells and phloem lineage cells, during postembryonic root development, facilitates phloem initiation in Arabidopsis. Knockout of CLE25 led to delayed protophloem formation, and in situ expression of an antagonistic CLE25G6T peptide compromised the fate-determining periclinal division of the sieve element precursor cell and the continuity of the phloem in roots. In stems of CLE25G6T plants the phloem formation was also compromised, and procambial cells were over-accumulated. Genetic and biochemical analyses indicated that a complex, consisting of the CLE-RESISTANT RECEPTOR KINASE (CLERK) leucinerich repeat (LRR) receptor kinase and the CLV2 LRR receptor- like protein, is involved in perceiving the CLE25 peptide. Similar to CLE25, CLERK was also expressed during early embryogenesis. Taken together, our findings suggest that CLE25 regulates phloem initiation in Arabidopsis through a CLERK-CLV2 receptor complex.

Contributions of Individual Amino Acid Residues to the Endogenous CLV3 Function in Shoot Apical Meristem Maintenance in Arabidopsis

As a peptide hormone, CLV3 restricts the stem cell number in shoot apical meristem （SAM） by interacting with CLV1/CLV2/CRN/RPK2 receptor complexes. To elucidate how the function of the CLV3 peptide in SAM maintenance is established at the amino acid （AA） level, alanine substitutions were performed by introducing point mutations to individual residues in the peptide-coding region of CLV3 and its flanking sequences. Constructs carrying such substitutions, expressed under the control of CLV3 regulatory elements, were transformed to the clv3-2 null mutant to evaluate their efficiencies in complementing its defects in SAMs in vivo. These studies showed that aspartate-8, histidine-11, glycine-6, proline-4, arginine-1, and proline-9, arranged in an order of importance, were critical, while threonine-2, valine-3, serine-5, and the previously assigned hydroxylation and arabinosylation residue proline-7 were trivial for the endogenous CLV3 function in SAM maintenance. In contrast, substitutions of flanking residues did not impose much damage on CLV3. Complementation of different alanine-substituted constructs was confirmed by measurements of the sizes of SAMs and the WUS expression levels in transgenic plants. These studies established a complete contribution map of individual residues in the peptide-coding region of CLV3 for its function in SAM, which may help to understand peptide hormones in general.

Defective mitochondrial function by mutation in THICK ALEURONE 1 encoding a mitochondrion-targeted single-stranded DNA-binding protein leads to increased aleurone cell layers and improved nutrition in rice

Cereal endosperm comprises an outer aleurone and an inner starchy endosperm.Although these two tissues have the same developmental origin,they differ in morphology,cell fate,and storage product accumulation,with the mechanism largely unknown.Here,we report the identification and characterization of rice thick aleurone 1(ta1)mutant that shows an increased number of aleurone cell layers and increased contents of nutritional factors including proteins,lipids,vitamins,dietary fibers,and micronutrients.We identified that the TA1 gene,which is expressed in embryo,aleurone,and subaleurone in caryopses,encodes a mitochondrion-targeted protein with single-stranded DNA-binding activity named OsmtSSB1.Cytological analyses revealed that the increased aleurone cell layers in ta1 originate from a developmental switch of subaleurone toward aleurone instead of starchy endosperm in the wild type.We found that TA1/OsmtSSB1 interacts with mitochondrial DNA recombinase RECA3 and DNA helicase TWINKLE,and downregulation of REC A3 or TWINKLE also leads to ta1-like phenotypes.We further showed that mutation in TA1/OsmtSSB1 causes elevated illegitimate recombinations in the mitochondrial genome,altered mitochondrial morphology,and compromised energy supply,suggesting that the OsmtSSB1-mediated mitochondrial function plays a critical role in subaleur one cell-fate determination in rice.

Defective mitochondrial function by mutation in THICK ALEURONE 1 encoding a mitochondrion-targeted single-stranded DNA-binding protein leads to increased aleurone cell layers and improved nutrition in rice

(Molecular Plant 14,1343–1361;August 22021)During the revision of the manuscript above,we inadvertently duplicated the picture of ta1 complementation transgenic seed from Figure 3D8 into Figure 1B5 and incorrectly specified that it was a picture of the wild type.The picture of Figure 1B5 was correct in the original submission,and no comments or suggestions were made from either the editors or the reviewers regarding the pictures involved.This image correction does not affect the figure legends,results,or any of the conclusions.Figure 1B5 has thus been rectified in the corrected picture below.The authors apologize for the error.