Floridoside是一种半乳糖基甘油化合物,可提供UDP-半乳糖,并在红藻中响应盐度时充当有机渗透压。重要的是,UDP-半乳糖池用于硫酸化细胞壁半乳聚糖合成,and,反过来,受叶状体发育以及挥发性生长调节剂诱导的孢子形成的影响,如乙烯和茉莉酸甲酯,在红海藻中。在这项研究中,我们通过基因表达控制半乳糖池和甘油酯池,在不同的繁殖阶段监测了氟菊酯储层的变化,并考虑了盐度条件的变化。由于UDP-半乳糖是从UDP-葡萄糖和葡萄糖-1P获得的,因此在合成了Floridoside之后进行了半乳糖-1-磷酸尿苷转移酶(GALT)的表达分析,并通过α-半乳糖苷酶基因表达,因为氟糖苷的降解是通过半乳糖残基的裂解而发生的。同时,甘油3-磷酸通过甘油3-磷酸脱氢酶(G3PD)与半乳糖甘油酯生物合成途径相连,单半乳糖二酰甘油酯合酶(MGDGS),和二半乳糖基二酰基甘油酯合酶(DGDGS)。我们的研究结果证实,低GALT转录本与定位生殖结构的thalli柔软度相关,以及在两种挥发性调节剂和甲硫氨酸存在下限制UDP-己糖的合成用于半乳聚糖主链合成。同时,α-半乳糖苷酶根据果壳成熟调节表达,我们在发展后期发现了高转录本,就像茉莉酸甲酯存在时发生的,与乙烯的早期阶段相比。关于酰基甘油酯池,G3PD的上调,MGGGS,和DGDGS基因表达在G.imbricata用MEJA处理支持脂质重塑,由于MGDGS和DGDGS的高水平转录物在囊果的晚期发育阶段提供膜稳定性。在三个自然收集的thalli发展阶段假设类似的行为-即,肥沃的,施肥,和肥沃-低于65psu盐度条件。在不育和受精的thalli中报道了α-半乳糖苷酶的低转录本和G3PD的高转录本,与35psu中的每个相应阶段相比,这与α-半乳糖苷酶的高转录本相反,而在可见囊果内的可育thalli中遇到的G3PD低。MGDGS和DGDGS没有报告显著变化。结论是,壳果和thallus发育阶段会影响半乳糖和甘油酯库,并对细胞壁多糖产生交织作用。
Floridoside is a galactosyl-glycerol compound that acts to supply UDP-galactose and functions as an organic osmolyte in response to salinity in Rhodophyta. Significantly, the UDP-galactose pool is shared for sulfated cell wall galactan synthesis, and, in turn, affected by thallus development alongside carposporogenesis induced by volatile growth regulators, such as ethylene and methyl jasmonate, in the red seaweed Grateloupia imbricata. In this study, we monitored changes in the floridoside reservoir through gene expression controlling both the galactose pool and glyceride pool under different reproductive stages of G. imbricata and we considered changing salinity conditions. Floridoside synthesis was followed by expression analysis of galactose-1-phosphate uridyltransferase (GALT) as UDP-galactose is obtained from UDP-glucose and glucose-1P, and through α-galactosidase gene expression as degradation of floridoside occurs through the cleavage of galactosyl residues. Meanwhile, glycerol 3-phosphate is connected with the galactoglyceride biosynthetic pathway by glycerol 3-phosphate dehydrogenase (G3PD), monogalactosyl diacylglyceride synthase (MGDGS), and digalactosyl diacylglyceride synthase (DGDGS). The results of our study confirm that low GALT transcripts are correlated with thalli softness to locate reproductive structures, as well as constricting the synthesis of UDP-hexoses for galactan backbone synthesis in the presence of two volatile regulators and methionine. Meanwhile, α-galactosidase modulates expression according to cystocarp maturation, and we found high transcripts in late development stages, as occurred in the presence of methyljasmonate, compared to early stages in ethylene. Regarding the acylglyceride pool, the upregulation of G3PD, MGDGS, and DGDGS gene expression in G. imbricata treated with MEJA supports lipid remodeling, as high levels of transcripts for MGDGS and DGDGS provide membrane stability during late development stages of cystocarps. Similar behavior is assumed in three naturally collected thalli development stages-namely, fertile, fertilized, and fertile-under 65 psu salinity conditions. Low transcripts for α-galactosidase and high for G3PD are reported in infertile and fertilized thalli, which is the opposite to high transcripts for α-galactosidase and low for G3PD encountered in fertile thalli within visible cystocarps compared to each of their corresponding stages in 35 psu. No significant changes are reported for MGDGS and DGDGS. It is concluded that cystocarp and thallus development stages affect galactose and glycerides pools with interwoven effects on cell wall polysaccharides.