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Lindsay, P. L.

Publications and source records attributed to Lindsay, P. L..

4 recordsLinked to original sources

Ontogenetic and time-course transcriptomic analyses of maize leaf primordia reveal regulators of transverse vein development

Leaf vein patterning varies greatly among land plants and is linked to leaf structure and function. C4 plants, such as maize, have a denser arrangement of veins than C3 plants, which is hypothesized to be a pre-adaptive trait for C4 photosynthesis. Therefore, understanding how leaf veins are patterned has implications for maximizing photosynthetic efficiency. Major maize leaf veins, called longitudinal veins, are arranged in parallel and are interconnected by transverse veins. Recent work has established molecular factors controlling longitudinal vein development; however, it is unknown how transverse veins are patterned. Here, we investigated how transverse veins establish connections within the maize vascular network. We performed anatomical analyses of transverse veins and found that despite asynchronous development, transverse veins fully integrate into the longitudinal vein network. Tracing the ontogeny of transverse vein development using the marker PIN1a-YFP, we found that two sets of two initial cells on opposing sides of adjacent longitudinal veins recruit intervening ground cells to form the provascular strand. Treatment with auxin inhibitors did not abolish transverse vein initiation, suggesting an auxin-independent pre-pattern for transverse vein initiation. Through time-course RNAseq of leaf primordia, we identified a transcriptional signature that precedes transverse vein development. Two genes that belong to this gene cluster, EREB41 and EREB114, are necessary for transverse vein formation. Together, our studies establish the ontogeny of maize transverse vein development and reveal how new vascular connections are specified, assembled, and integrated into an existing vascular network.

plant biology↗

Antagonistic interactions between CLAVATA receptors shape maize ear development

Meristem activity is controlled by the CLAVATA (CLV) signaling pathway, which involves a suite of leucine rich receptor (LRR) receptors, receptor-like proteins and CLV- EMBRYO SURROUNDING REGION (CLE) peptide ligands. FASCIATED EAR 3 (FEA3) is a leucine rich receptor (LRR) receptor-like protein important for meristem maintenance in maize, and acts independently of canonical CLV receptors. Weak alleles of fea3 can increase yield-related traits in maize, so understanding how FEA3 controls inflorescence development can maximize its potential as a crop improvement target. To identify FEA3s interaction network, we used TurboID-based proximity labeling in maize meristems, and identified a putative co-receptor, BARELY ANY MERISTEM 1D (BAM1D). BAM1D and FEA3 proximity labeling proteomes shared over 100 proteins, including many signaling proteins, suggesting they feed into a common signaling pathway. fea3 was epistatic to bam1d in the control of IM size, supporting the idea that FEA3 and BAM1D interact physically. However, fea3 and bam1d act antagonistically, because fea3 mutants had larger inflorescence meristems (IMs), whereas bam1d mutants produced smaller IMs. Together, this study demonstrates how in vivo TurboID-based proximity labeling clarifies complex genetic interactions between CLV receptors and expands our knowledge of downstream signaling components of CLV signaling pathways, which are largely uncharacterized. Our findings support the notion that multiple, partially overlapping CLV receptor complexes coordinately control meristem maintenance.

plant biology↗

Medicago truncatula CORYNE regulates inflorescence meristem branching, nutrient signaling, and arbuscular mycorrhizal symbiosis

The CLAVATA signaling pathway regulates plant development and plant-environment interactions. CLAVATA signaling consists of mobile, cell-type or environment-specific CLAVATA3/ESR-related (CLE) peptides, which are perceived by a receptor complex consisting of leucine-rich repeat receptor-like kinases such as CLAVATA1 and receptor-like proteins such as CLAVATA2, which often functions with the pseudokinase CORYNE (CRN). CLAVATA signaling has been extensively studied in various plant species for its role in meristem maintenance and in legumes for modulating root interactions with nitrogen-fixing rhizobia. Some signaling proteins involved in development and nodulation, including CLAVATA1, also regulate plant interactions with mutualistic arbuscular mycorrhizal (AM) fungi. However, our knowledge on AM symbiosis regulation by CLAVATA signaling remains limited and only a handful of genetic regulators have been identified. Here we report that Medicago truncatula CRN controls inflorescence meristem branching and negatively regulates root interactions with AM fungi. MtCRN functions partially independently of the AM autoregulation signal MtCLE53. Transcriptomic data revealed that crn roots display signs of perturbed nutrient, symbiosis, and stress signaling, suggesting that MtCRN plays various roles in plant development and interactions with the environment.

plant biology↗

Rapid expression of COVID-19 proteins by transient expression in tobacco.

In 2020 we suffered from a major global pandemic caused by the SARS-CoV-2 coronavirus. Efforts to contain the virus include the development of rapid tests and vaccines, which require a ready supply of viral proteins. Here we report the production of two SARS-CoV-2 proteins by transient transformation of tobacco, leading to high expression within three days, and subsequent purification of the intact proteins. Such efforts may help to develop testing resources to alleviate the major impacts of this global pandemic.

plant biology↗