Variation for heterodimerization and nuclear localization among known and novel oil palm SHELL alleles

Abstract

Summary Oil palm breeding involves crossing dura and pisifera palms to produce tenera progeny with greatly improved oil yield. Oil yield is controlled by variant alleles of a type II MADS‐box gene, SHELL, that impact the presence and thickness of the endocarp, or shell, surrounding the fruit kernel. We identified six novel SHELL alleles in noncommercial African germplasm populations from the Malaysian Palm Oil Board. These populations provide extensive diversity to harness genetic, mechanistic and phenotypic variation associated with oil yield in a globally critical crop. We investigated phenotypes in heteroallelic combinations, as well as SHELL heterodimerization and subcellular localization by yeast two‐hybrid, bimolecular fluorescence complementation and gene expression analyses. Four novel SHELL alleles were associated with fruit form phenotype. Candidate heterodimerization partners were identified, and interactions with EgSEP3 and subcellular localization were SHELL allele‐specific. Our findings reveal allele‐specific mechanisms by which variant SHELL alleles impact yield, as well as speculative insights into the potential role of SHELL in single‐gene oil yield heterosis. Future field trials for combinability and introgression may further optimize yield and improve sustainability.

Programmed Cell Death May Be Involved in the Seedless Phenotype Formation of Oil Palm

“…It has been proposed that different fruit forms in oil palm are controlled by SHELL , a type II MADS-box gene that controls ovule identity and seed development in Arabidopsis ( Singh et al, 2013 , 2020 ). More so, MADS-box genes have a role in pollen fertilization and the development of seedless fruits ( Klap et al, 2017 ; Takisawa et al, 2018 ; Tang et al, 2019 ; Wei et al, 2019 ; Molesini et al, 2020 ).…”

“… Singh et al (2013) reported that SHELL gene is responsible for endocarp development, which differentiates three fruit forms: Dura, Tenera, and Pisifera in oil palm. The authors found two independent mutations in MADS-box transcription factor SHELL , a homolog of the MADS-box gene SEEDSTICK (also known as AGAMOUS-Like 11, AGL11 ), which acts on the ovule identity and seed development in Arabidopsis ( Singh et al, 2013 , 2020 ). In addition, MADS-box genes have also been reported to be implicated in pollen fertilization and the development of seedless fruits ( Klap et al, 2017 ; Takisawa et al, 2018 ; Tang et al, 2019 ; Wei et al, 2019 ; Molesini et al, 2020 ).…”

Fatty acid isoprenoid alcohol ester synthesis in fruits of the African Oil Palm (Elaeis guineensis)

“…The variation in total amounts of FAPE and FAGGE in the kernel was low as compared to the mesocarp where the contents of FAPE and FAGGE varied by a factor of two compared to the control line Deli x La Mé. It has been shown that the variation for a given trait in a population is maximal for the population where the highest genetic variation is expected, that is usually the place of its origin (Singh et al, 2020). Indeed, Oil Palms have been used by humans for several thousand years in the region of its origin in West Africa, but commercial cultivation of elite lines started in East Asia only about 100 years ago (Sambanthamurthi, 2000).…”

Short Communication: MADS-box genes expression in seedlings of Elaeis guineensis Jacq. resistance to Ganoderma boninense

“…Advances in molecular technology were allowed the molecular studies of the flowering genes that play a role in flowering (Santos et al 2020;Uguru et al 2020). In most plants, the flowering process is controlled by many genes, such as SQUA, AGL, GLO, AG, and DEF genes that are mutually reliable (Singh et al 2020). The structural character from E. guineensis to the MADS-box genes, namely SQUAMOSA, DEFICIENS, GLOBOSA, AGAMOUS, and AGL2 subfamily (Adam et al 2006).…”

“…On oil palm, the molecular development of flowers is still limited. Singh et al (2020) have been reported oil yield was controlled alleles type II MADS-box genes (SHELL) to impact of presence that thickness from endocarp, shell, and fruit of kernel. Recently, Li et al (2020) have been reported EgMADS21 was expressed to early mesocarp development stages from oil palm fruits to a negative correlation.…”