CoNPR1 and CoNPR3.1 are involved in SA‐ and MeSA‐ mediated growth of the pollen tube in Camellia oleifera

Abstract

Salicylic acid (SA) is a plant hormone involved in a series of growth, development, and stress responses in plants. Nonexpressor of pathogenesis‐related genes 1 (NPR1) is the core regulatory gene in the process of SA‐mediated systemic acquired resistance (SAR). Whether NPR1 is involved in pollen tube growth mediated by SA and its derivative MeSA (methyl salicylate) remains to be explored. Here, we found that the contents of endogenous SA and MeSA in self‐ or cross‐pollinated pistils changed significantly, and exogenous SA and MeSA significantly promoted pollen germination and pollen tube elongation of Camellia oleifera at lower concentrations. CoNPR1, CoNPR3.1, CoNPR3.2, and CoNPR5 were identified, and they were all located in the nucleus. A high level of consistency was observed across the phylogenetic relationships, gene structures, and functional domains, indicating a clear division of function, as observed in other species. The expression levels of CoNPR1, CoNPR3.1, CoNPR3.2, and CoNPR5 in self‐ and cross‐pollinated pistils had certain regularity. Furthermore, they exhibited tissue‐specific expression pattern. CoNPR1 and CoNPR3.1 were expressed in pollen tubes, whose expression was regulated by SA or MeSA, and their expression patterns were basically consistent with the trend of pollen germination. These results indicate that SA and MeSA are involved in the pollen tube growth of C. oleifera, and CoNPRs may play an important role therein.

Hormone and transcriptomic analysis revealed that ABA and BR are key factors in the formation of inter‐subgeneric hybridization barrier in water lily

“…For example, in Brassicaceae, the levels of ROS in the stigma play a role in regulating both self-incompatibility and interspecies hybrid barriers (Zhang et al 2021, Huang et al 2023. In Arabidopsis, variations in ROS levels in the stigma directly impact pollen hydration and germination on the transmitting tract cells (Liu et al 2021). Therefore, we propose that the accumulation of ROS mediated by Ca 2+ signaling in the stigma of water lily may be one of the key factors contributing to the formation of reproductive barriers in inter-subgeneric hybrids.…”

Enhancing the accumulation of linoleic acid and α-linolenic acid through the pre-harvest ethylene treatment in Camellia oleifera

“…The main product of C. oleifera seeds, used to extract edible vegetable oil. The by-products of C. oleifera, such as tea meal and fruit shells, can be processed into important chemicals and other industrial raw materials to manufacture soap, green fertilizer, activated carbon, and so forth (Xing et al, 2011;Lu et al, 2021). C. oleifera oil (tea oil) is commonly known as 'eastern olive oil', because more than 90.0% components are unsaturated fatty acids (Wu et al, 2020).…”

“…C. oleifera oil (tea oil) is commonly known as 'eastern olive oil', because more than 90.0% components are unsaturated fatty acids (Wu et al, 2020). Further, the oleic acid (OA) content accounts for fatty acids more than 80.0%, but the contents of linoleic acid (w-6 fatty acid, LA) and a-linolenic acid (w-3 fatty acid, ALA) which are essential for human body are only approximately 8.0% and 0.2%, respectively (Gong et al, 2020;Lu et al, 2021;Zhang et al, 2021). Therefore, increasing the LA and ALA contents in tea oil can potentially improve the oil quality.…”

Co-regulatory effects of hormone and mRNA–miRNA module on flower bud formation of Camellia oleifera

“…The expression of FT showed diurnal rhythms under both long-day and short-day conditions and was photoperiod-dependent (Lei et al, 2017). Previous studies on C. oleifera buds were mostly concerned with sepal, petal, estrogen, and stamen formation after the formation of the flower primordium and investigated the effects of hormones and key genes during the differentiation of flowers (Li et al, 2013;Lu et al, 2021). However, the floral primordium had already formed, and the subsequent differentiation process had limited influence on the number of C. oleifera flowers.…”