Uniparental Inheritance of Salinity Tolerance and Beneficial Phytochemicals in Rice

Abstract

Salinity stress is one of the most problematic constraints to significantly reduce rice productivity. The Saltol QTL (quantitative trait locus) has been known as one among many principal genes/QTLs responsible for salinity tolerance in rice. However, the introgression of the Saltol QTL from the donor (male) into the recipient (female) cultivars induces great recessions from the progeny generation, which results in heavy fieldwork and greater cost and time required for breeding. In this study, the F1 generation of the cross TBR1 (female cultivar, salinity tolerant) × KD18 (male cultivar, salinity susceptible) was preliminarily treated with N-methyl-N-nitrosourea (MNU) to induce the mutants M1. Results on physiological traits show that all the M2 (self-pollinated from M1) and M3 (self-pollinated from M2) individuals obtain salinity tolerant levels as the recurrent TBR1. Twelve SSR (simple sequence repeat) markers involved in the Saltol QTL (RM493, RM562, RM10694, RM10720, RM10793, RM10852, RM13197, RM201, RM149, RM508, RM587, and RM589) and other markers related to yield-contributing traits and disease resistance, as well as water and nitrogen use, have efficacy that is polymorphic. The phenotype and genotype analyses indicate that the salinity tolerant Saltol QTL, growth parameter, grain yield and quality, pest resistance, water and nitrogen use efficacy, and beneficial phytochemicals including antioxidants, momilactone A (MA) and momilactone B (MB) are uniparentally inherited from the recurrent (female) TBR1 cultivar and stabilized in the M2 and M3 generations. Further MNU applications should be examined to induce the uniparental inheritance of other salinity tolerant genes such as OsCPK17, OsRMC, OsNHX1, OsHKT1;5 to target rice cultivars. However, the mechanism of inducing this novel uniparental inheritance for salinity tolerance by MNU application needs elaboration.

Salinity Treatments Promote the Accumulations of Momilactones and Phenolic Compounds in Germinated Brown Rice

“…On the other hand, the highest TFC (11.06 mg RE/g DW) was detected in B2, while the lowest TFC (2.54 mg RE/g DW) was found in A2. Previous studies indicated that TPC and TFC increased in rice seedlings under salinity effects [ 38 , 39 , 40 ], which might be due to the upregulation of genes encoding the major biosynthetic enzymes (e.g., phenylalanine ammonia lyase and chalcone synthase) in plant responses to biotic stresses [ 33 , 41 , 42 ]. In this study, TPC and TFC were remarkably stimulated in treatments with 75 mM salinity.…”

“…This might be due to the differences in genetic diversity among tested rice varieties. In fact, different rice varieties (tolerant and susceptible cultivars) exhibit dissimilar mechanisms in phenolic accumulation to cope with stress conditions [ 33 , 38 , 39 , 40 ]. On the other hand, the present study revealed a notable decrease in the quantities of these phenolics in GBR when exposed to extreme levels of salinity (150 mM).…”

Transcription Factors Rc and OsVP1 Coordinately Regulate Preharvest Sprouting Tolerance in Red Pericarp Rice

“…VP1 / ABI3 plays a significant role during seed development and dormancy inception. ,− From the mapping population derived from the cross between Osvp1 and Kasalath, Rc partially limited the pigmentation and sprouting of RcRcvp1vp1 progenies (Figure a). This limitation could be a result of uniparental inheritance or maternal effect on pericarp color . First, we identified the red pericarp progenies depended on Rc.…”

Genetic Diversity of Asian Rice (Oryza sativa L.) Germplasm for Direct Seeding in Response to Soil Salinity Stress at Germination Stage

“…within the cell and is especially responsive at the seedling stage. In the previous study it was found to have the 5 alleles with PIC value of 0.69 20 . In our study the results are comparable with the previous nding and marker RM493 showed 6 alleles with PIC value of 0.72.…”