University of Birmingham (UK) scientists have created a plant that rejects its own pollen or pollen of close relatives, according to research published in the journal Science today (5 November 2015).
Self-pollination or ‘selfing’ can be bad for a plant resulting in inbreeding and less healthy offspring. This breakthrough could be used to breed stronger more resilient crops faster and at lower cost; a new approach in the quest for a secure and plentiful food supply.
The team took the self-fertile plant thale cress – Arabidopsis thaliana – a relative of cabbages, cauliflowers and oilseed rape, and made it self-incompatible by the transfer of just two genes from poppies that enable the recipient plant to recognize and reject its own pollen whilst permitting cross-pollination. Such conversion of a selfing plant to a self-incompatible one has been a long term goal of self-incompatibility research.
The basic anatomy of most flowers means the male pollen is produced next to the female reproductive organs running the real risk of self-pollination, rather than receiving pollen from a different flower transported by the wind or on an insect. When pollen lands on the stigma of a flowering plant the pollen germinates and develops a pollen tube which grows through the stigma and other female tissues and then enters the plant’s ovary to affect fertilization. If this involves self-pollen, it results in inbreeding, which can result in a shrinking gene pool and unhealthy offspring. The Birmingham team have made major progress over the last few years in understanding the mechanisms by which the field poppy, Papaver rhoeas, avoids this.
A central role is played by two self-incompatibility (SI) proteins: a “receptor”, PrpS, made by the pollen and a signal protein called PrsS that is produced by the stigma. Plants have their identities specified by the exact version of PrpS and PrsS they produce. In this way, flowers can recognize that they are interacting with “self” through the PrpS/PrsS interaction, which triggers several chemical signals that cause inhibition of pollen involving a mechanism called “programmed cell death”, resulting in incompatible pollen being told to commit suicide before they germinate and begin extending their pollen tube. Conversely, if the pollen and stigma are expressing non-matching SI genes, “self” recognition does not occur and pollination is successful.
The research team had previously transferred the pollen PrpS gene from the Field Poppy into Arabidopsis thaliana, which is self-fertile. When pollen grains expressing PrpS were exposed to matching female recombinant PrsS proteins, SI-specific recognition occurred, leading to a self-incompatibility reaction with the hallmark features of those observed in poppies.
This latest finding, published in the journal, Science, went one step further by putting the female PrsS gene from the poppy into Arabidopsis thaliana plants and showing that this gene is expressed in A. thaliana pistils and functions to reject matching “self” pollen. Then they demonstrated that Arabidopsis thaliana plants co-expressing both the pollen and stigma SI genes exhibit complete rejection of self-pollen. This demonstrates for the first time that just these two poppy SI genes are sufficient to establish a robust self-incompatibility in a highly divergent self-compatible species which is over 100 million years away in evolutionary distance.
Professor Noni Franklin-Tong from the University of Birmingham’s School of Biosciences, and lead author of the study said: ‘This is a major achievement, as this has been an elusive, important goal of plant scientists for decades. I’ve often been asked why we were working on poppy, which is not related to any crop plant, because it was assumed that one would have to use closely related genes from relatives of crop plants to achieve this. Now we can say that our persistence has paid off. Our findings open up questions about how plant signalling networks have evolved, as it suggests that by putting in these two genes that act as a lock and key, we can get another signalling pathway and physiological outcome to be specified .’
This study represents a major advance in the quest to utilize self-incompatibility systems as a potential alternative means to breed hybrid plants – plants whose ‘hybrid vigour’ gives them better yields and strength than their parents.
The Latest on: Hybrid plants
via Google News
The Latest on: Hybrid plants
- Chrysler Pacifica Hybrid Earns Top SUV/Minivan Honors in 2020 AAA Car Guideon August 3, 2020 at 8:39 am
Chrysler Pacifica Hybrid Limited takes top spot in the 2020 AAA Car Guide SUV/Minivan category; Pacifica Hybrid also scores top-t ...
- Toyota's hybrid strategy will spreadon August 2, 2020 at 9:00 pm
Toyota is hoping its broad hybridization strategy will pay off for other models as it has for the RAV4 Hybrid, which in June outsold the nonhybrid version of the crossover for the first time. The ...
- Common reasons why some plants don’t thrive in eastern Idahoon August 2, 2020 at 3:51 pm
We live in an arid, high altitude desert, and as part of that, we have high diurnal temperature swings, meaning the days get hot and the nights get cold. This is hard on plants that are not native to ...
- MINI Plant Oxford has built more than 11,000 MINI Electricson August 2, 2020 at 9:48 am
MINI Plant Oxford has hit a significant milestone by building more than 11,000 MINI Electrics since production began ...
- ZooAmerica launches hybrid, mostly virtual version of its long-running Zoo Campon July 30, 2020 at 5:01 pm
ZooAmerica in Hershey is taking its annual summertime ZooCamp virtual, with a hybrid twist. First- through sixth-grade ... It is located on 11 acres of landscape featuring native plants and ...
- This hybrid offshore wind farm will be a green energy ‘supergroup’on July 30, 2020 at 12:13 pm
Oil giant Shell and Dutch utility Eneco have won the tender to build a super-hybrid offshore wind farm in the Netherlands.
- Engineering a carbon-negative power planton July 29, 2020 at 8:58 am
Katherine Hornbostel, assistant professor of mechanical engineering and materials science at the University of Pittsburgh's Swanson School of Engineering, and her team received $800,283 in funding ...
- Nashoba heading to hybrid schoolson July 24, 2020 at 2:05 am
Come fall, students in the Nashoba school district may be studying hybrids – from plant biology to automotive technology. But they ...
- Hybrid Power Solutions Market Trends, Size, Forecast - 2019-2025on July 23, 2020 at 5:40 am
The global hybrid power solutions market is expected to grow at a CAGR ... This is led by the most attractive Feed-in-Tariffs (FITs) and utility-scale power plants. Japan’s Government passed a FIT for ...
- More Big Solar-Battery Plants Being Built in Nevada Deserton July 22, 2020 at 9:07 am
Capital Dynamics has begun building $1.3 billion in solar projects in Nevada that feature battery storage. Abundant sun and falling battery prices have transformed the state into a hub for large ...
via Bing News