Symbiotic gene Sym33 is located on linkage group I

Pisum Genetics

2006—Volume 38

Research Papers

Symbiotic gene Sym33 is located on linkage group I

Tsyganov, V.E.¹*, Rozov, S.M.², ¹Dept. of Biotech., All–Russia Res. Inst. for Agric. Microbiol.

Borisov, A.Y.¹ and Tikhonovich, I.A.¹ St. Petersburg,. Russia

*corresponding author ²Inst. of Cytol. and Genet., Novosibirsk, Russia

In pea 40 genes controlling pea-Rhizobium symbiosis have been identified up to now using genetical approaches (1). Nineteen of these have been localized on the genetic map (2, 7, 9, 14). Most of these genes control early nodule developmental stages (6, 12). Only three symbiotic genes controlling late nodule developmental stages, sym13, sym27 and sym31, have been mapped to date (5, 8, 9). In addition, the late symbiotic gene sym26 was linked with a DNA marker found in an unclassified linkage group (13). Some of these genes are also involved in the interaction of the pea host with arbuscular mycorrhizal fungi (1).

In this study we localized late symbiotic gene sym33, which have been identified in mutant SGEFix^--2. It has been shown that gene sym33 controls the endocytosis of bacteria into host-cell cytoplasm from infection droplets and differentiation of infection threads in young nodule tissue (11). Mutation in the gene sym33 also influences mycorrhiza development, decreasing mycorrhizal colonization of roots and delaying arbuscule development at low temperature (3, 4).

For the mapping of Sym33 we first crossed the mutant SGEFix^--2 with the line NGB1238. Segregation at locus Sym33 was analyzed in F₃ plants to identify F₂ plants homozygous and heterozygous by wild type and mutant alleles of Sym33. Joint segregation analysis showed barely significant linkage between Sym33 and

Table 1. Joint segregation data in the F populations of crosses 1) NGB1238 (d) x SGEFix^--2 (sym33),

2) SGEFix^--2 (sym33) x NGB1515 (d, I), 3) NGB2715 (d, I, af) x SGEFix^--2 (sym33), 4) (Wt-10584 (aero, I) x

SGEFix^--2 (sym33)).


	Gene	Phase		Number of progeny with designated phenotype*			Total Joint c2		Prob.	RCV SE
Cross pairs		Phase	A/B A/h A/b h/B h/h h/b a/B		a/h	a/b	Total Joint c2		Prob.	RCV SE
d -1 sym33		R	13	47 28 2	6	15	111	08.6	<0.025	37.4 5.5
2	d -sym33	R	10	7 8 17 31 13 4	9	20	119	18.2	<0.005	35.5 4.1
	I -sym33	C	28	39 23 3	8	18	119	13.5	<0.005	31.9 5.0
	d -sym33	R	16	20 8 20 66 21 12	14	18	195	16.6	<0.005	39.8 3.4
3	I -sym33	C	45	79 22 3	21	25	195	29.7	<0.0001	27.0 3.6
	af -sym33	R	18	17 1 26 57 14 4	26	32	195	50.2	<0.0001	27.5 2.8
	d -sym33	R	20	11 4 8 24 7 5	7	14	100	27.4	<0.0001	28.9 4.0
4	I -sym33	C	40	60 19 8	7	20	154	24.9	<0.0001	30.9 4.3
	aero -sym33	R	25	10 1 10 36 8 9	16	29	144	60.6	<0.0001	24.6 3.0

¹A/a first gene; B/b second gene; h, heterozygous. When both genes are dominant, the capital letter stands for the dominant allele. When the second gene is codominant, the capital A stands for the dominant allele of the first gene and capital B for an allele of the second gene in coupling with A. When both genes are codominant, the capital letter stands for an allele of the first parent.

The calculations were made using S.M. Rozov’s programs PLANT and CROSS and Piet Stam’s program JoinMap (10).

Pisum Genetics

2006—Volume 38

Research Papers

marker d (linkage group I) (Table 1). In order to

confirm the position of Sym33 on linkage group I

mutant SGEFix^--2 was crossed with lines

NGB1515, NGB2715 and Wt10584. In the cross

with line NGB1515, linkage between Sym33 and Fig.1. The map of the d—sym33—i region. The distances

both markers d and I was found (Table 1). In the are given in cM.

cross with line NGB2715, linkage between Sym33

and three markers d, i and af was also shown (Table 1). The cross with the line Wt10584 showed linkage

between sym33 and markers d, i and aero. A map of this region was constructed based on our data (Fig. 1).

Previously, symbiotic mutations nod3, sym2, sym5, sym10, sym19, Enod7, Enod40, Lb (14) and sym35 (2) have been

mapped to linkage group I. Sym33 appears to be localized near the symbiotic loci Sym5, Sym19 and Enod40.

Currently, linkage group I contains a greater number of genes involved with symbiotic associations than any

other linkage group in pea. This prevalence of symbiotic loci may indicate a special role in the establishment

of pea-Rhizobium symbiosis for this chromosome.

Acknowledgements: This work was financially supported by Russian Federal Agency for Science (state contract no. 02.445.11.7492), grant of the President of Russia (H-9744.2006.4), Russian Fund for Basic Research (04-04-48457; 06-04-89000-HBO (a).

1. Borisov, A.Y., Danilova, T.N., Koroleva, T.A., Naumkina, T.S., Pavlova, Z.B., Pinaev, A.G., Shtark, O.Y., Tsyganov, V.E., Voroshilova, V.A., Zhernakov, A.I., Zhukov, V.A. and Tikhonovich, I.A. 2004. Biologia. 59 Suppl: 137-144.

2. Borisov, A.Y., Madsen, L.H., Tsyganov, V.E., Umehara, Y., Voroshilova, V.A., Batagov, A.O., Sandal, N., Frederiksen, A., Schauser, L, Ellis, N., Tikhonovich, I.A. and Stougaard, J. 2003. Plant Physiol. 131: 1009-1017.

3. Jacobi ,L.M., Petrova, O.S., Tsyganov, V.E., Borisov, AY. and Tikhonovich, I.A. 2003a. Mycorrhiza. 13: 3-7.

4. Jacobi, L.M., Zubkova, L.A., Barmicheva, E.M., Tsyganov, V.E., Borisov, AY. and Tikhonovich,I.A. 2003b. Mycorrhiza. 13: 9-16.

5. Kneen, B.E., LaRue, T.A., Hirsch, A.M., Smith, C.A. and Weeden, N.F. 1990. Plant Physiol. 94: 899-905.

6. Kneen, B.E., Weeden, N.F. and LaRue, T.A. 1994. J. Heredity. 85: 129-133.

7. Koroleva, T.A., Voroshilova, V.A., Tsyganov, V.E., Borisov, AY. and Tikhonovich, I.A. 2001 Pisum Genet. 33: 30-31.

8. Rozov, S.M., Borisov, AY. and Tsyganov, V.E. 1994. Pisum Genet. 26: 24-25.

9. Rozov, S.M., Borisov, AY., Tsyganov, V.E. and Kosterin, O.E. 1999. Pisum Genet. 31: 55-57.

10. Stam, P. 1993. Plant J. 3: 739-744.

11. Tsyganov, V.E., Morzhina, E.V., Stefanov, S.Y., Borisov, AY., Lebsky, V.K. and Tikhonovich, I.A. 1998. Mol. Gen. Genet. 256: 491-503

12. Tsyganov, V.E., Voroshilova, V.A., Priefer, U.B., Borisov, AY. and Tikhonovich, I.A. 2002. Ann. Bot. 89: 357-366.

13. Ul-Hasan, M., Weeden, N.F., Temnykh, SV. and LaRue, T.A. 1996. Pisum Genet. 28: 29-30.

14. Weeden, N.F., Ellis, T.H.N., Timmerman-Vaughan, G.M., Swiecicki, W.K., Rozov, S.M. and Berdnikov, V.A. 1998. Pisum Genet. 30: 1-4.