Chloroplast Engineering of Pathogen Resistance

Through plastid genome engineering, we have achieved agronomic transformation of many important crops, such as herbicide resistance, drought tolerance, salt tolerance, insect resistance, pathogen resistance, nitrogen fixation, nutrition, and cytoplasmic male sterility. Here, Lifeasible is committed to providing crops with reliable and economical chloroplast genetic engineering solutions to combat phytopathogenic microorganisms.

Introduction

Plant pathogens remain major constraints on the growth of many crops and pose a significant threat to global food security. It is therefore highly desirable to design plants that are resistant to pathogenic bacteria and fungi. Since chloroplasts play an important role in plant immunity, correspondingly, chloroplasts have also become targets of pathogens. Pathogenic microorganisms interfere with chloroplast function and structure by delivering small molecules and effector proteins into plant cells. Amphipathic peptides such as magainin have known antimicrobial properties. Among them, MSI-99 is an amphiphilic α-helical molecule with affinity for negatively charged phospholipids found in the outer membranes of bacteria and fungi. Upon contact with these membranes, individual peptides aggregate to form pores, resulting in microbial lysis. Recently, MSI-99 was successfully expressed in the chloroplast genome.

Fig. 1. Microorganisms interfere with chloroplast function. (Yang F, et al., 2021)

Our Solutions

Although pathogens are a major constraint on the growth of many crops, only a small fraction of these genetically modified crops have disease resistance traits. Our engineers have been working hard to develop genes for pathogen resistance. Here, we also provide other proven solutions for chloroplast engineering of pathogen resistance.

(1) Enhanced resistance to fungal and viral pathogens by increasing salicylic acid levels in transgenic plants.

• We introduced the argK gene of P. syringae pv. Phaseolicola into tobacco chloroplasts using a plastid transit peptide (pea rbcS) and Agrobacterium transformation.
• We introduced entC and pmsB to tobacco chloroplasts.

(2) Improved crop resistance to viral infection by increasing protein yield.
We introduced the AMPs retrocyclin101 (RC101) and Protegrin-1 (PG1) into tobacco plastids for overexpression.

Attractive Advantages of Our Solutions

• The use of plastid genetic engineering to combat pathogens in crop plants is an ideal solution.
• MSI-99 is expressed through the chloroplast genome to achieve high dose release at the point of infection.
• MSI-99 is expressed at high levels and retains biological activity against Pseudomonas syringae.
• Growth and development of transgenic plants were not affected by MSI-99 overexpression in chloroplasts.
• The outer membrane is an important and highly conserved part of all microbial cells, and microorganisms do not develop resistance to these peptides.

Lifeasible's goal is to provide customers around the world with fully customized chloroplast engineered solutions for pathogen resistance. Please contact us to discuss further details to ensure your next success.

References

1. Yang F, Xiao K, Pan H, et al. (2021) Chloroplast: the emerging battlefield in plant–microbe interactions[J]. Frontiers in Plant Science. 12: 637853.
2. Daniell H, Khan MS, Allison L. (2002) Milestones in chloroplast genetic engineering: an environmentally friendly era in biotechnology. Trends Plant Sci. 7(2):84-91.