Chinese fir genome and the evolution of gymnosperms

Abstract

Seed plants comprise angiosperms and gymnosperms. The latter includes gnetophytes, cycads, Ginkgo, and conifers. Conifers are distributed worldwide, with 630 species distributed across eight families and 70 genera. Their distinctiveness has triggered much debate on their origin, evolution, and phylogenetic placement among seed plants. To better understand the evolution of gymnosperms and their relation to other seed plants, we report here a high-quality genome sequence for a tree species, Chinese fir (Cunninghamia lanceolata), which has excellent timber quality and high aluminum adaptability and is a member of Cupressaceae with high levels of heterozygosity. We assembled an 11.24 Gb genome with a contig N50 value of 2.15 Mb and anchored the 10.89 Gb sequence to 11 chromosomes. Phylogenomic analyses showed that cycads sister to Ginkgo, which place to sister in all gymnosperm lineages, and Gnetales within conifers sister to Pinaceae. Whole-genome duplication (WGD) analysis showed that the ancestor of seed plants has differentiated into angiosperms and gymnosperms after having experienced a WGD event. The ancestor of extant gymnosperm has experienced a gymnosperm-specific WGD event and the extant angiosperms do not share a common WGD before their most recent common ancestor diverged into existing angiosperms lineages. Analysis of the MADS-box gene family of C. lanceolata revealed the developmental mechanism of the reproductive organs in C. lanceolata, which supported the (A)B(C) model of the development of gymnosperms reproductive organs. In addition, astringent seeds and shedding of whole branches (with withered leaves) might be a strategy of C. lanceolata that evolved during long-term adaptation to an aluminum-rich environment. The findings also reveal the molecular regulation mechanism of shade tolerance in C. lanceolata seedlings. Our results improve the resolution of ancestral genomic features within seed plants and the knowledge of genome evolution and diversification of gymnosperms.

Revealing Further Insights into Astringent Seeds of Chinese Fir by Integrated Metabolomic and Lipidomic Analyses

“…The application of exogenous GABA could effectively reduce ROS levels and modulate phytohormone cross-talk, thereby enhancing tolerance to multiple stresses [44]. Research by Lin et al showed that the exogenous application of astringent seed extracts could enhance the adaptability of Chinese fir seedlings to stressful high-aluminum conditions [11]. Here, the substantial accumulation of GABA in astringent seeds may play a role in this process.…”

“…Over the past decades, extensive investigations have been conducted on the issue of astringent seeds in Chinese fir, including anatomical analysis [2,5] and identification of intrinsic components [6], physiological and biochemical changes [5,7,8], as well as ecological factors contributing to the production of astringent seeds [4,9,10]. Generally, the process of astringent seed formation can be divided into two stages: embryo abortion and astringent substance accumulation [11]. The process of astringent seed abortion seems to be closely related to the pollination process.…”

Development of Ir-cR8-albumin nanomedicine toward the interventional treatment of liver cancer

“…Due to the insidious onset of liver cancer in most patients, HCC is often diagnosed at an advanced stage, resulting in poor prognostic outcomes [7,8] Hepatic artery infusion chemotherapy (HAIC) is an important treatment modality for advanced-stage liver cancer. However, the severe systemic toxicity of the rst-line chemotherapeutic agent oxaliplatin has led to poor tolerability in patients at this stage, resulting in forced discontinuation of treatment [9,10] . Therefore, there is an urgent need to develop alternative drugs that are safe, effective and have low toxicity, especially for patients with advanced liver cancer.…”

Tangeretin, An Active Flavonoid in Citrus Peel, Alleviates Cisplatin-Induced Cardiotoxicity via the Activation of AMPK and the Prevention on Mitochondrial Dysfunction

“…Cisplatin was found to be the rst metal-based anticancer agent, which was approved by the U.S. Food and Drug Administration (FDA) in 1978 [1]. It has been widely used as a rst-line chemotherapy drug for clinical treatment against various types of solid organ tumors when monotherapy or combination therapy with other compounds [2][3][4][5]. However, dose-dependent cardiotoxicity signi cantly increased the risk of cardiovascular complications including cardiomyopathy, hypertension, cardiac ischemia, and arrhythmias [6][7][8].…”