Browsing by Author "Brajendra, P."

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Novel major QTLs associated with low soil phosphorus tolerance identified from the Indian rice landrace, Wazuhophek
(PLOS, 2021) Kale, Ravindra Ramrao; Durga Rani, Ch. V.; Anila, M.; Mahadeva Swamy, H. K; Bhadana, V. P.; Senguttuvel, P.; Subrahmanyam, D.; Ayyappa Dass, M.; Swapnil, K.; Anantha, M. S.; Punniakotti, E.; Prasanna, B. Laxmi; Rekha, G.; Sinha, P.; Kousik, M. B. V. N.; Dilip, T.; Hajira, S. K.; Brajendra, P.; Mangrauthia, S. K.; Gireesh, C.; Tuti, Mangaldeep; Mahendrakumar, R.; Giri, Jitender; Singh, Pawandeep; Sundaram, R. M.
With an objective of mapping novel low soil P (Phosphorus) tolerance loci in the non-Pup1 type donor rice line, Wazuhophek, we screened a recombinant inbred line (RIL) mapping population consisting of 330 lines derived from the cross Wazuhophek x Improved Samba Mahsuri (which is highly sensitive to low soil P) in a plot with low soil P for tolerance associated traits. Molecular mapping with SSR markers revealed a total of 16 QTLs (seven major and nine minor QTLs), which are associated with low soil P tolerance related traits. Interestingly, a QTL hotspot, harbouring 10 out of 16 QTLs were identified on the short arm of chromosome 8 (flanked by the makers RM22554 and RM80005). Five major QTLs explaining phenotypic variance to an extent of 15.28%, 17.25%, 21.84%, 20.23%, and 18.50%, associated with the traits, plant height, shoot length, the number of productive tillers, panicle length and yield, respectively, were located in the hotspot. Two major QTLs located on chromosome 1, associated with the traits, total biomass and root to shoot ratio, explaining 15.44% and 15.44% phenotypic variance, respectively were also identified. Complex epistatic interactions were observed among the traits, grain yield per plant, days to 50% flowering, dry shoot weight, and P content of the seed. In-silico analysis of genomic regions flanking the major QTLs revealed the presence of key putative candidate genes, possibly associated with tolerance.
Tolerance of Oryza sativa to low phosphate is associated with adaptive changes in root architecture and metabolic exudates
(Elsevier B.V., 2025) Srivastava, Akanksha; Gupta, Amber; Bishi, Sujit K.; Akhila, Pole; Latha, P.C.; Subrahmanyam, D.; Brajendra, P.; Anantha, M.S.; Ch, Suvarna Rani; Sakhare, Akshay S.; Bhadana, Vijai Pal; Giri, Jitender; Neeraja, C.N.; Sundaram, R.M.; Mangrauthia, Satendra K.
The optimum usage of fertilizers is key for the sustainable agriculture. Among nutrients, phosphorus (P) is critical for plant growth and development. Due to complete reliance on natural resources (rock phosphate) for P, the availability of P fertilizers is emerging as a global challenge for crop cultivation. Moreover, the excess application of P fertilizers in rice, mostly grown under flooded conditions, leads to water pollution called eutrophication. In this study, we employed a mutagenesis approach for developing and characterizing rice EMS (ethyl meth anesulfonate) mutants with better adaptation to low soil P conditions. One such mutant of rice cultivar Nagina 22, named NH4824, was characterized comprehensively at seedling and reproductive growth stages under hy droponic and field conditions. The mutant exhibits low soil P tolerance due to combined adaptive changes in root system architecture, anatomy, organic acid exudates, plasma membrane (PM) H+-ATPase activity, induced expression of P transporter genes, and efficient mobilization and partitioning of P in different plant tissues. The activity of antioxidant enzymes and better photosynthesis suggested relatively less stress experienced by NH4824 than N22 under low soil P conditions. These insights are highly useful to develop P use efficient crop cultivars through breeding or genome editing approaches.