Table III. Genes encoding LD proteins in Arabidopsis thaliana.
Levels of transcripts (reads per kilobase million), on a relative basis, of genes within a lineage are simplified for generalization; they vary according to the organ, stage of development, etc. Levels of transcripts of genes encoding LD proteins of different lineages are, in general, SH = SL = T > > U and other nonoleosin proteins. T oleosin transcripts in flower buds are 1 order of magnitude lower than SL or SH oleosin transcripts in maturing seed; however, T oleosin transcripts are restricted to one tapetum cell layer in a flower bud, whereas SL and SH oleosin transcripts are present in most cells in a maturing seed. Transcript levels were obtained from the RNA sequencing databasea (http://ncbi.nlm.nih.gov/) and individual reports cited in the text, and the information was supplemented with TAIR-eFP database (https://www.arabidopsis.org/). Genes encoding oleosins, dioxygenase, LD Associated Proteins, and OB Associated Proteins are numbered according to those in reports cited in the text. Genes encoding the other LD proteins are listed and numbered according to their occurrence on chromosomes 1 to 5 and in the 5′ to 3′ direction.
| Protein Names | No. of Genes within the Lineage | Organs with Highest Transcript Level | Transcript Level, Relative within the Lineage | Gene Accession Numbers | Comments |
|---|---|---|---|---|---|
| Oleosin | |||||
| U oleosin | 3 | Seed, pollen | U1 = U2 = U3 | At1g48990 (U1) | |
| At3g18570 (U2) | |||||
| At2g25890 (U3) | |||||
| SL oleosin | 2 | Seed | SL2 > SL1 | At3g27660 (SL1) | |
| At5g40420 (SL2) | |||||
| SH oleosin | 3 | Seed | SH2 > SH1 > SH3 | At3g01570 (SH1) | |
| At4g25140 (SH2) | |||||
| At5g51210 (SH3) | |||||
| T oleosin | 9 | Anther tapetum | T5 > T3 > T6 | At5g07470 (T1) | Eight of the nine genes in tandem |
| At5g07520 (T2) | |||||
| At5g07530 (T3) | |||||
| At5g07540 (T4) | |||||
| At5g07550 (T5) | |||||
| At5g07560 (T6) | |||||
| At5g07571 (T9) | |||||
| At5g07600 (T7) | |||||
| At5g61610 (T8) | |||||
| Caleosin | 7 | C1 and C2 in anther; C3, C4, and C6 in seed; C5 in petal and sepal | C6 > C5 > C1 | At1g23240 (C1) | C1 and C2 in tandem; C3 and C4 in tandem |
| At1g23250 (C2) | |||||
| At1g70670 (C3) | |||||
| At1g70680 (C4) | |||||
| At2g33380 (C5) | |||||
| At4g26740 (C6) | |||||
| At5g29560 (C7) | |||||
| Steroleosin | 8 | S3, S5, S7, and S8 in seed; S4 and S6 in stem and embryo | S7 > S3 > S8 | At3g47350 (S1) | S1 and S2 in tandem; S4 to S8 in tandem |
| At3g47360 (S2) | |||||
| At4g10020 (S3) | |||||
| At5g50590 (S4) | |||||
| At5g50600 (S5) | |||||
| At5g50690 (S6) | |||||
| At5g50700 (S7) | |||||
| At5g50770 (S8) | |||||
| Dioxygenase | 2 | D1 in root; D2 ubiquitous; increased during senescence and biotic stresses | D1 > D2 | At3g01420 (D1) | |
| At1g73680 (D2) | |||||
| LD Associated Protein | 3 | Ubiquitous; increased during abiotic stresses | SR3 > > SR1 = SR2 | At1g67360 (SR1) | Also termed small rubber particle protein, SRPP |
| At2g47780 (SR2) | |||||
| At3g05500 (SR3) | |||||
| OB Associated Protein | 5 | Seed (late maturation) | OB1 > OB5 > OB2 | At1g05510 (OB1) | |
| At1g29680 (OB2) | |||||
| At2g31985 (OB3) | |||||
| At4g18920 (OB4) | |||||
| At5g45690 (OB5) | |||||
| Lipase | 4 | Ubiquitous | SDP1 = SDP2 = SGI | At5g04040 (SDP1) | CGI in peroxisome, not LD |
| At3g57140 (SDP1L) | |||||
| At1g33270 (SDP2) | |||||
| At4g24160 (CGI58L) | |||||
| PAP | 3 | Ubiquitous | PAP2 > PAP1 > PAP3 | At4g04020 (PAP1) | Plastid-lipid-associated protein; all in plastids, not LD |
| At4g22240 (PAP2) | |||||
| At2g35490 (PAP3) |
The RNA sequencing database from the National Center for Biotechnology Information included SRX424380 for 7- to 8-d seed, SRX424383 for 9- to 10-d seed, SRX424386 for 11- to 12-d seed, SRX463620 for leaf, SRX1425915 for root, SRX399566 for stage 6 flower bud, and SRX257730 for stage 12 flower bud.