Hormone analysis and candidate genes identification associated with seed size in Camellia oleifera

Abstract

Camellia oleifera is an important woody oil species in China. Its seed oil has been widely used as a cooking oil. Seed size is a crucial factor influencing the yield of seed oil. In this study, the horizontal diameter, vertical diameter and volume of C. oleifera seeds showed a rapid growth tendency from 235 days after pollination (DAP) to 258 DAP but had a slight increase at seed maturity. During seed development, the expression of genes related to cell proliferation and expansion differ greatly. Auxin plays an important role in C. oleifera seeds; YUC4 and IAA17 were significantly downregulated. Weighted gene co-expression network analysis screened 21 hub transcription factors for C. oleifera seed horizontal diameter, vertical diameter and volume. Among them, SPL4 was significantly decreased and associated with all these three traits, while ABI4 and YAB1 were significantly increased and associated with horizontal diameter of C. oleifera seeds. Additionally, KLU significantly decreased (2040-fold). Collectively, our data advances the knowledge of factors related to seed size and provides a theoretical basis for improving the yield of C. oleifera seeds.

Transcriptome and Anatomical Comparisons Reveal the Effects of Methyl Jasmonate on the Seed Development of Camellia oleifera

“…Previous studies identified that the cell number and cell area of the seed coat, endosperm, and embryo could co-determine seed size. 15,17 The results demonstrated that 0.5 mM of MeJA increased the cell number and cell area in the outer seed coat (early development stage) and embryo (236−334 DAP), thereby resulting in the production of larger seeds (Figure 2B The known signaling pathways that controlled the seed size 13,33,59 were detected in C. oleifera seeds (Figure 4). In MAPK signaling, NPK1 has been proved to regulate cell and seed sizes, 79 which were increased by MeJA in C. oleifera seeds and the relative increase showed positive correlations with the relative increase in the seed size and cell area of the outer seed coat and embryo.…”

“…The known signaling pathways that controlled the seed size ,, were detected in C. oleifera seeds (Figure ).…”

“…Five seeds from each C. oleifera under treatment were selected and photographed. Seed volume was measured as described previously, 59 and an electronic balance was used to measure seed weight. Three biological replicates were measured for each treatment group, with 100 seeds per replicate.…”

“…The known signaling pathways that controlled the seed size 13,33,59 were detected in C. oleifera seeds (Figure 4). In MAPK signaling, NPK1 has been proved to regulate cell and seed sizes, 79 which were increased by MeJA in C. oleifera seeds and the relative increase showed positive correlations with the relative increase in the seed size and cell area of the outer seed coat and embryo.…”

Genomic and genetic advances of oiltea-camellia (Camellia oleifera)

“…The expressions of 21 hub transcription factors were related to the fruit vertical diameter, horizontal diameter and volume of the fruit. Among these genes, the expressions of SPL4 , KLU , ABI4 and YAB1 were significantly associated with these fruit traits ( Ji et al., 2022 ). In addition, the fruit size of oiltea-camellia is also associated with the number of ploids in the genome, possibly due to the increased expression of the genes controlling fruit size.…”