3.4. Knockdown of OsLTPL36 resulted

3.4. Knockdown of OsLTPL36 resulted in the decrease of lipid and
protein content in seed
In order to analyze the reason why seed weight reduced signifi-
cantly in OsLTPL36-RNAi lines, we examined several major storage
substances of the seeds. The results demonstrated that the seed
total lipid contents in three OsLTPL36-RNAi lines (i5-5, i8-3 and
i23-2) were 27.70, 28.33 and 31.52% lower than that in WT respectively
(Fig. 4D, Table S2). Crude fat acid component of rice include
palmitic, oleic, and linoleic acids and several other components. The
palmitic acid is the saturated fatty acid with the highest content
in rice seed [5], and oleic acid is a predominant monounsaturated
fatty acid of rice seed oil. Thus, we further tested the content of
five main CFAs composition using GC–MS. Among them, C16:0
(palmitic acid), C18:0 (stearic acid), C18:1 (oleic acid) and C18:2
(linoleic acid) were significantly reduced in three OsLTPL36-RNAi
lines. The C18:3 (linolenic acid) in OsLTPL36-RNAi lines was also
reduced compared with WT (Table 2). These significant differences
of CFAs between OsLTPL36-RNAi lines and WT plant suggested
that OsLTPL36 might be involved in the uptake or transport of
lipid during seed development. Concomitant with the decrease
in lipids content, the seed protein content was reduced by 2.68,
2.31 and 4.81 mg/g in the i5-5, i8-3 and i23-2 lines, respectively,compared with WT (Fig. 4A and B). The declined content of protein
in OsLTPL36-RNAi lines seed led us to investigate the aleurone layer
ofthe seeds. The thickness of aleurone layer was examined by staining
with methylene blue, revealing a significantly thinner aleurone
layer in the RNAi lines seeds than that in WT (Fig. 6). However, no
difference in total seed starch content per equal seed weight was
observed between OsLTPL36-RNAi and WT lines.