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bioRxiv · 10.1101/2022.04.14.488389

PvC3H29 interacts with and inhibits DNA binding of PvNAPs to finetune leaf senescence in switchgrass (Panicum virgatum)

Xie, Z.·Yu, G.·Lei, S.·Wang, H.·Xu, B.
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Abstract

Finetuning the progression of leaf senescence is important for plants fitness in nature, while staygreen with delayed leaf senescence has been considered as a valuable agronomic trait in crop genetic improvement. In this study, a switchgrass CCCH-type Zinc finger gene, PvC3H29, was characterized as a suppressor of leaf senescence that over-expressing or suppressing the gene led to delayed or accelerated leaf senescence, respectively. Transcriptomic analysis marked that chlorophyll catabolic pathway genes were involved in the PvC3H29-regulated leaf senescence. PvC3H29 was a nucleus-localized protein with no transcriptional activity. By Y2H screening, we identified its interacting proteins, including a pair of paralogous transcription factors, PvNAP1&2. Over-expressing the PvNAPs led to precocious leaf senescence at least partially by directly targeting and transactivating chlorophyll catabolic genes to promote chlorophyll degradation. PvC3H29, through protein-protein interaction, repressed the DNA-binding efficiency of PvNAPs and alleviated its transactivating effect on downstream genes, thereby functioned as a brake in the progression of leaf senescence. Moreover, over-expressing PvC3H29 resulted in up to 47% higher biomass yield and improved biomass feedstock quality, reiterating the importance of leaf senescence regulation in the genetic improvement of switchgrass and other feedstock crops. One-sentence summaryPvC3H29 interacts with transcription factors, PvNAP1&2, to inhibit their transactivation on chlorophyll catabolism and leaf senescence in switchgrass.

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Xie, Z., Yu, G., Lei, S., Wang, H., Xu, B.. 2022-04-15. PvC3H29 interacts with and inhibits DNA binding of PvNAPs to finetune leaf senescence in switchgrass (Panicum virgatum). https://doi.org/10.1101/2022.04.14.488389

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